Drill pipe and optimization thereof

ABSTRACT

A drill pipe comprises a drill pipe body having a drill pipe body outer diameter and a drill pipe body inner diameter, wherein the drill pipe body outer diameter is from about 5.1-inches to about 5.4-inches and the drill pipe body inner diameter is from about 4.4-inches to about 4.6-inches; and a tool joint comprising a rotary shoulder box connection; wherein the drill pipe has an optimization ratio and wherein the optimization ratio is at least about 0.68 for a production hole from about 7⅞-inches to about 12¼-inches. Methods of using the drill pipe are also disclosed.

PRIOR RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Nonprovisional patentapplication Ser. No. 16/680,242, filed on Nov. 11, 2019, which is acontinuation-in-part of U.S. Nonprovisional patent application Ser. No.15/924,709, filed on Mar. 19, 2018, which claims the benefit of U.S.Provisional Patent Application Ser. No. 62/554,347 entitled “IMPROVEDROTARY SHOULDER CONNECTIONS FOR THREADED PIPE CONNECTIONS,” filed onSep. 5, 2017.

Further, this application is a continuation-in-part of U.S.Nonprovisional patent application Ser. No. 16/680,242, filed on Nov. 11,2019, which is also a continuation-in-part of U.S. Nonprovisional patentapplication Ser. No. 15/926,431, filed on Mar. 20, 2018, which claimsthe benefit of U.S. Provisional Patent Application Ser. No. 62/554,707entitled “IMPROVED ROTARY SHOULDER CONNECTIONS FOR THREADED PIPECONNECTIONS,” filed on Sep. 6, 2017.

FEDERALLY SPONSORED RESEARCH STATEMENT

Not Applicable (N/A)

REFERENCE TO MICROFICHE APPENDIX

N/A

FIELD OF INVENTION

The present invention relates generally to a drill pipe with a rotaryshoulder connection and methods thereof and, more particularly, to animproved drill pipe with a rotary shoulder connection with primary andsecondary angled and/or curved shoulder features for threaded pipeconnections in various drill strings and methods thereof.

BACKGROUND OF THE INVENTION

Conventional American Petroleum Institute (API) 5-inch drill pipesuffers from poor hydraulic efficiencies and mechanical performance. TheAPI 5-inch drill pipe has a tendency to buckle due to poor stiffness.

Standard (typical) double-shoulder connections and standard (typical)single-shoulder connections suffer from the problem of box “swell”(e.g., box material yields) due to tapered threads, included threadprofile angle and high generated axial compressive loads. The box swellforces force the primary shoulder of the box connection outward, causingdeformation of and/or permanent damage to the box connection.

Standard (typical) double-shoulder connections and standard (typical)single-shoulder connections also suffer from the problem of pincollapse. The pin collapse forces push a portion of the pin nose inward,causing deformation of and/or permanent damage to the pin connection.

This combination of box swell (e.g., box material yields) and pincollapse can lead to misalignment of the box threads and the pinthreads, as well as permanent damage to the box connection and/or thepin connection. Over time, the box threads become misaligned with thepin threads, causing damage to the box threads and/or the pin threads.

Further, this combination of box swell (e.g., box material yields) andpin collapse, in conjunction with high alternating axial, torsional, andbending loads, can lead to premature fatigue failure of the standard(typical) double-shoulder connection and standard (typical)single-shoulder connection, damage to the box threads and/or the pinthreads, and permanent deformation of the box connection and/or the pinconnection to reduce the effects of box swell (e.g., box materialyields) and pin collapse.

Thus, an improved drill pipe with an improved double-shoulder connectionand an improved single-shoulder connection are needed to eliminate theseproblems.

SUMMARY OF THE INVENTION

In an embodiment, a drill pipe comprises a drill pipe body having adrill pipe body outer diameter and a drill pipe body inner diameter.

In an embodiment, the drill pipe comprises a drill pipe length.

In an embodiment, the drill pipe length is from about 25-feet to about50-feet. In an embodiment, the drill pipe length is about 31.5-feet. Inan embodiment, the drill pipe length is about 45-feet to about 47-feet.

In an embodiment, the drill pipe is made from one or more of low alloysteels, stainless steels, super alloys, titanium alloys, copper alloys,cobalt alloys, aluminum alloys, and variations thereof. In anembodiment, the drill pipe is made from one or more of low alloy steels,stainless steels, and variations thereof.

In an embodiment, the drill pipe body outer diameter is from about5.1-inches to about 5.4-inches. In an embodiment, the drill pipe bodyouter diameter is about 5.25-inches.

In an embodiment, the drill pipe body inner diameter is from about4.4-inches to about 4.6-inches. In an embodiment, the drill pipe bodyinner diameter is about 4.528-inches.

In an embodiment, the drill pipe body comprises a drill pipe body wallthickness.

In an embodiment, the drill pipe body wall thickness is from about0.352-inches to about 0.370-inches. In an embodiment, the drill pipebody wall thickness is about 0.361-inch.

In an embodiment, the tool joint comprises a tool joint box having atool joint box outer diameter and a tool joint box inner diameter, and atool joint pin having a tool joint pin outer diameter and a tool jointpin inner diameter.

In an embodiment, the tool joint box outer diameter is from about6.1-inches to about 6.4-inches and the tool joint box inner diameter isfrom about 3.4-inches to about 3.6-inches. In an embodiment, the tooljoint box outer diameter is about 6.25-inches and the tool joint boxinner diameter is about 3.5-inches.

In an embodiment, the tool joint pin outer diameter is from about6.1-inches to about 6.4-inches and the tool joint pin inner diameter isfrom about 3.4-inches to about 3.6-inches. In an embodiment, the tooljoint pin outer diameter is about 6.25-inches and the tool joint pininner diameter is about 3.5-inches.

In an embodiment, the tool joint comprises a box hardband having a boxhardband outer diameter, and a pin hardband having a pin hardband outerdiameter.

In an embodiment, the box hardband outer diameter is from about6.3-inches to about 6.6-inches. In an embodiment, the box hardband outerdiameter is about 6.438-inches.

In an embodiment, the pin hardband outer diameter is from about6.3-inches to about 6.6-inches. In an embodiment, the pin hardband outerdiameter is about 6.438-inches.

In an embodiment, the tool joint box comprises a tapered elevatorshoulder having a tapered elevator shoulder angle.

In an embodiment, the tapered elevator shoulder angle is from about 16degrees to about 20 degrees. In an embodiment, the tapered elevatorshoulder is about 18 degrees.

In an embodiment, the tool joint pin comprises a tapered pin shoulderhaving a tapered pin shoulder angle.

In an embodiment, the tapered pin shoulder angle is from about 16 degreeto about 36-degrees. In an embodiment, the tapered pin shoulder angle isfrom about 16-degrees to about 20 degrees. In an embodiment, the taperedpin shoulder is about 18 degrees.

In an embodiment, the tool joint box comprises a drill pipe box weldneck in a region of a drill pipe box body upset having a drill pipe boxbody upset inner diameter.

In an embodiment, the drill pipe box body upset inner diameter is fromabout 3.66-inches to about 3.85-inches. In an embodiment, the drill pipebox body inner diameter is about 3.752-inches.

In an embodiment, the tool joint pin comprises a drill pipe pin weldneck in a region of a drill pipe pin body upset having a drill pipe pinbody upset inner diameter.

In an embodiment, the drill pipe pin body upset inner diameter is fromabout 3.66-inches to about 3.85-inches. In an embodiment, the drill pipepin body upset inner diameter is about 3.752-inches.

In an embodiment, the tool joint box comprises a tool joint box length.

In an embodiment, the tool joint box length is from about 15-inches toabout 19-inches. In an embodiment, the tool joint box length is about17-inches.

In an embodiment, the tool joint pin comprises tool joint pin length.

In an embodiment, the tool joint pin length is from about 12.5-inches toabout 15.5-inches. In an embodiment, the tool joint pin length is about14-inches.

In an embodiment, a method of using a drill pipe comprises providing aplurality of drill pipe as discussed herein and connecting the pluralityof the drill pipe to produce a drill string.

In an embodiment, a tool joint comprises a rotary shoulder boxconnection, as discussed herein.

In an embodiment, the rotary shoulder connection comprises a rotaryshoulder connection length.

In an embodiment, the rotary shoulder connection length is from about4.275-inches to about 5.225-inches. In an embodiment, the rotaryshoulder connection length is about 4.75-inches.

In an embodiment, a rotary shoulder connection comprises an angledprimary shoulder and/or an angled secondary shoulder.

In an embodiment, the rotary shoulder connection comprises: a boxconnection having a box axis, a pin connection having a pin axis and aprimary shoulder connection at a first end of the box connection and afirst end of the pin connection.

In an embodiment, the box connection has a box outer radius, a boxcounter bore radius and a box inner radius, and box threads having a boxthread form cut along a box taper.

In an embodiment, the pin connection has a pin outer radius, a pincylinder radius and a pin nose radius, and pin threads having a pinthread form cut along a pin taper to align with the box threads insidethe box connection.

In an embodiment, the primary shoulder connection comprises: a primarybox shoulder at a primary box angle with respect to a firstperpendicular to the box axis at a first end point of the boxconnection; and a primary pin shoulder at a primary pin angle withrespect to the first perpendicular to the pin axis at the first endpoint of the pin connection. In an embodiment, the first end point isequal to a datum intersection.

In an embodiment, the primary box angle is about 0 degrees and theprimary pin angle is about 0 degrees.

In an embodiment, the primary box angle is from greater than or equal toabout 0 degrees to less than or equal to about 15 degrees. In anembodiment, the primary box angle is from greater than or equal to about0 degrees to less than or equal to about 10 degrees. In an embodiment,the primary box angle is about 5 degrees. In an embodiment, the primarybox angle is about 0 degrees.

In an embodiment, the primary pin angle is from greater than or equal toabout 0 degrees to less than or equal to about 15 degrees. In anembodiment, the primary pin angle is from greater than or equal to about0 degrees to less than or equal to about 10 degrees. In an embodiment,the primary pin angle is about 5 degrees. In an embodiment, the primarypin angle is about 0 degrees.

In an embodiment, the primary box angle is about equal to the primarypin angle to form a first seal.

In an embodiment, the primary box angle is slightly different than theprimary pin angle to form a first seal. In an embodiment, the first sealis a gas-tight seal.

In an embodiment, the primary box shoulder contacts the primary pinshoulder to form a first seal. In an embodiment, the primary boxshoulder is conical shaped (outside of cone, male) and the primary pinshoulder is conical shaped (inside of cone, female).

In an embodiment, the box thread form comprises a first box threadcrest, a second box thread crest, a first box thread flank, a second boxthread flank, a box included angle between the first box thread flankand the second box thread flank, and a box thread root. In anembodiment, the box thread form is selected from the group consisting ofsquare, triangular, trapezoidal, and variations thereof. In anembodiment, the first box thread crest and/or the second box threadcrest is circular, square, triangular or trapezoidal shaped. In anembodiment, the first box thread flank and/or the second box threadflank are concave, convex, or straight shaped. In an embodiment, the boxthread root is circular, square, triangular or trapezoidal shaped. In anembodiment, the box included angle is from about 29 degrees to about 90degrees. In an embodiment, the box thread form is triangular and the boxincluded angle is about 60 degrees.

In an embodiment, the pin thread form comprises a first pin threadcrest, a second pin thread crest, a first pin thread flank, a second pinthread flank, a pin included angle between the first pin thread flankand the second pin thread flank, and a pin thread root. In anembodiment, the pin thread form is selected from the group consisting ofsquare, triangular, trapezoidal, and variations thereof. In anembodiment, the first pin thread crest and/or the second pin threadcrest is circular, square, triangular or trapezoidal shaped. In anembodiment, the first pin thread flank and/or the second pin threadflank are concave, convex, or straight shaped. In an embodiment, the pinthread root is circular, square, triangular or trapezoidal shaped. In anembodiment, the pin included angle is from about 29 degrees to about 90degrees. In an embodiment, the pin thread form is triangular shaped andthe pin included angle is about 60 degrees.

In an embodiment, the box threads and/or the pin threads are treated byone or more of cold rolling, shot peening, phosphating, fluoropolymercoating, ceramic coating, chrome plating, anodizing, and variationsthereof. In an embodiment, the box threads and/or the pin threads aretreated by one or more of cold rolling, shot peening, fluoropolymercoating, and anodizing.

In an embodiment, the rotary shoulder connection further comprises oneor more of a box boreback, a box stress relief groove and a pin stressrelief groove.

In an embodiment, the rotary shoulder connection is made from one ormore of low alloy steels, stainless steels, super alloys, titaniumalloys, copper alloys, cobalt alloys, aluminum alloys, and variationsthereof. In an embodiment, the rotary shoulder connection is made fromone or more of low alloy steels, stainless steels, and variationsthereof.

In an embodiment, the rotary shoulder connection is applied to one ormore of drill pipe, heavy weight drill pipe, drill collars, pup joints,crossover subs, saver subs, bit subs, float subs, pump-in subs, insideblowout preventers, top drive shafts, top drive valves, safety valves,kelly valves, hoisting equipment, swivels, fishing tools, mud motors,rotary steerable tools, drill bits, directional drilling bottom holeassembly components, measurement while drilling components, loggingwhile drilling components, well cleanout tools, completion tools, andvariations thereof. In an embodiment, the rotary shoulder connection isapplied to one or more of drill pipe, heavy weight drill pipe, drillcollars, pup joints, and variations thereof.

In an embodiment, the rotary shoulder connection further comprises: asecondary shoulder connection at a second end of the box connection anda second end of the pin connection. In an embodiment, the secondaryshoulder connection comprises: a secondary box shoulder at a secondarybox angle with respect to a second perpendicular to the box axis at thesecond end point of the box connection; and a secondary pin shoulder ata secondary pin angle with respect to the second perpendicular to thepin axis at the second end point of the pin connection.

In an embodiment, the second end is offset a second distance from thefirst end. In an embodiment, the second distance is from about 2 inchesto about 8 inches. In an embodiment, the second distance is a connectionlength.

In an embodiment, the secondary box angle is about 0 degrees and thesecondary pin angle is about 0 degrees.

In an embodiment, the secondary box angle is from greater than or equalto about 0 degrees to less than or equal to about 15 degrees. In anembodiment, the secondary box angle is from greater than or equal toabout 0 degrees to less than or equal to about 10 degrees. In anembodiment, the secondary box angle is about 5 degrees. In anembodiment, the secondary box angle is about 0 degrees.

In an embodiment, the secondary pin angle is from greater than or equalto about 0 degrees to less than or equal to about 15 degrees. In anembodiment, the secondary pin angle is from greater than or equal toabout 0 degrees to less than or equal to about 10 degrees. In anembodiment, the secondary pin angle is about 5 degrees. In anembodiment, the secondary pin angle is about 0 degrees.

In an embodiment, the secondary box angle is about equal to thesecondary pin angle to form a torque shoulder.

In an embodiment, the secondary box angle is slightly different than thesecondary pin angle to form a torque shoulder that is a second seal. Inan embodiment, the torque shoulder or the second seal is a gas-tightseal.

In an embodiment, the secondary box shoulder contacts the secondary pinshoulder to form a torque shoulder. In an embodiment, the secondary boxshoulder is conical shaped (outside of cone, male) and the secondary pinshoulder is conical shaped (inside of cone, female).

In an embodiment, the box thread form comprises a first box threadcrest, a second box thread crest, a first box thread flank, a second boxthread flank, a box included angle between the first box thread flankand the second box thread flank, and a box thread root. In anembodiment, the box thread form is selected from the group consisting ofsquare, triangular, trapezoidal, and variations thereof. In anembodiment, the first box thread crest and/or the second box threadcrest is circular, square, triangular or trapezoidal shaped. In anembodiment, the first box thread flank and/or the second box threadflank are concave, convex, or straight shaped. In an embodiment, the boxthread root is circular, square, triangular or trapezoidal shaped. In anembodiment, the box included angle is from about 29 degrees to about 90degrees. In an embodiment, the box thread form is triangular and the boxincluded angle is about 60 degrees.

In an embodiment, the pin thread form comprises a first pin threadcrest, a second pin thread crest, a first pin thread flank, a second pinthread flank, a pin included angle between the first pin thread flankand the second pin thread flank, and a pin thread root. In anembodiment, the pin thread form is selected from the group consisting ofsquare, triangular, trapezoidal, and variations thereof. In anembodiment, the first pin thread crest and/or the second pin threadcrest is circular, square, triangular or trapezoidal shaped. In anembodiment, the first pin thread flank and/or the second pin threadflank are concave, convex, or straight shaped. In an embodiment, the pinthread root is circular, square, triangular or trapezoidal shaped. In anembodiment, the pin included angle is from about 29 degrees to about 90degrees. In an embodiment, the pin thread form is triangular shaped andthe pin included angle is about 60 degrees.

In an embodiment, the box threads and/or the pin threads are treated byone or more of cold rolling, shot peening, phosphating, fluoropolymercoating, ceramic coating, chrome plating, anodizing, and variationsthereof. In an embodiment, the box threads and/or the pin threads aretreated by one or more of cold rolling, shot peening, fluoropolymercoating, and anodizing.

In an embodiment, the rotary shoulder connection further comprises oneor more of a box boreback, a box stress relief groove and a pin stressrelief groove.

In an embodiment, the rotary shoulder connection is made from one ormore of low alloy steels, stainless steels, super alloys, titaniumalloys, copper alloys, cobalt alloys, aluminum alloys, and variationsthereof. In an embodiment, the rotary shoulder connection is made fromone or more of low alloy steels, stainless steels, and variationsthereof.

In an embodiment, the rotary shoulder connection is applied to one ormore of drill pipe, heavy weight drill pipe, drill collars, pup joints,crossover subs, saver subs, bit subs, float subs, pump-in subs, insideblowout preventers, top drive shafts, top drive valves, safety valves,kelly valves, hoisting equipment, swivels, fishing tools, mud motors,rotary steerable tools, drill bits, directional drilling bottom holeassembly components, measurement while drilling components, loggingwhile drilling components, well cleanout tools, completion tools, andvariations thereof. In an embodiment, the rotary shoulder connection isapplied to one or more of drill pipe, heavy weight drill pipe, drillcollars, pup joints, and variations thereof.

In an embodiment, a method of using a rotary shoulder connectioncomprises: providing a rotary shoulder connection; and applying therotary shoulder connection to one or more products. In an embodiment,the rotary shoulder connection may be the improved double-shoulderconnection with an angled primary shoulder or the improvedsingle-shoulder connection with an angled primary shoulder, as discussedabove.

In an embodiment, the method further comprises tightening the rotaryshoulder connection between one of more products to form the first seal.

In an embodiment, the method further comprises tightening the rotaryshoulder connection between the one or more products to form the firstseal and the torque shoulder.

In an embodiment, a method for determining a primary shoulder locationcomprises: locating a pitch line parallel to a connection box/pin taper;locating a first intersection of a pitch diameter and the pitch line;locating a first perpendicular to the connection box/pin axis at thefirst intersection; locating a second perpendicular to the connectionbox/pin axis at a first distance towards a primary box/pin shoulder fromthe first perpendicular; and locating a second intersection of the pitchline and the second perpendicular.

In an embodiment, the method for determining a primary shoulder locationfurther comprises defining a primary box/pin angle with respect to thesecond perpendicular at the second intersection.

In an embodiment, the first distance is from about 0.5 inch to about2.50 inches. In an embodiment, the first distance is from about 0.625inch to about 2.250 inches. In an embodiment, the first distance isabout 0.625 inch.

In an embodiment, a method for determining a secondary shoulderconnection location comprises: locating a pitch line parallel to aconnection box/pin taper; locating a first intersection of a pitchdiameter and the pitch line; locating a first perpendicular to theconnection box/pin axis at the first intersection; locating a secondperpendicular to the connection box/pin axis at a first distance towardsa primary box/pin shoulder from the first perpendicular; locating asecond intersection of the pitch line and the second perpendicular;locating a third perpendicular to the connection box/pin axis at asecond distance toward a secondary box/pin shoulder; and locating athird intersection of a pin nose outer diameter and the thirdperpendicular.

In an embodiment, the second distance may be about 2 inches to about 8inches. In an embodiment, the second distance is a connection length.

In an embodiment, the method for determining a secondary shoulderlocation further comprises optionally, defining a primary box/pin anglewith respect to the second perpendicular at the second intersection anddefining a secondary box/pin angle with respect to the thirdperpendicular at the third intersection.

In an embodiment, the method for determining a secondary shoulderlocation comprises defining a secondary box/pin angle with respect tothe third perpendicular at the third intersection.

In an embodiment, a rotary shoulder connection comprises a curvedprimary shoulder and/or a curved secondary shoulder.

In an embodiment, the rotary shoulder connection comprises: a boxconnection having a box axis, wherein the box connection has a box outerradius, a box counter bore radius and a box inner radius, and boxthreads having a box thread form cut along a box taper; a pin connectionhaving a pin axis, wherein the pin connection has a pin nose innerradius, a pin outer radius, a pin cylinder radius and a pin nose radius,and pin threads having a pin thread form cut along a pin taper to alignwith the box threads inside the box connection; and a primary shoulderconnection at a first end of the box connection and a first end of thepin connection.

In an embodiment, the primary shoulder connection comprises: a primarybox shoulder with a first curved profile defined by a primary axial boxradius height, a primary box center point and a primary box radius; anda primary pin shoulder with a second curved profile defined by a primaryaxial pin radius height, a primary box center point and a primary pinradius. In an embodiment, the primary box shoulder contacts the primarypin shoulder to form a first seal.

In an embodiment, the first end point is coplanar with a first referenceplane.

In an embodiment, the primary axial box radius height is from about0.000 inch to about the length of the primary box radius in inches; andthe primary axial pin radius height is from about 0.000 inch to aboutthe length of the primary pin radius in inches.

In an embodiment, the primary box center point is located at abouthalf-way between a box counter bore diameter and a pin bevel diameter;and the primary pin center point is located at about half-way betweenthe box counter bore diameter and the pin bevel diameter.

In an embodiment, the primary box radius is greater than about [(pinbevel diameter−box counter bore diameter)/4] inches; and the primary pinradius is greater than about [(box bevel diameter−box counter borediameter)/4] inches. In an embodiment, the primary box radius is greaterthan about [(pin bevel diameter−box counter bore diameter)/4] inches. Inan embodiment, the primary axial box radius is about equal to theprimary pin radius to form the first seal. In an embodiment, the primarybox radius is slightly different than the primary pin radius to form thefirst seal.

In an embodiment, the primary box shoulder is convex shaped and theprimary pin shoulder is concave shaped.

In an embodiment, the primary box shoulder has one or more of a firstflat region at an inner edge of the first curved profile and a firstangled flat region at an outer edge of the first curved profile; and theprimary pin shoulder has one or more of a second flat region at an inneredge of the first curved profile and a third flat region at an outeredge of the first curved profile.

In an embodiment, the rotary shoulder connection further comprises: asecondary shoulder connection at a second end of the box connection anda second end of the pin connection. In an embodiment, the secondaryshoulder connection comprises: a secondary box shoulder with a thirdcurved profile defined by a secondary axial box radius height, asecondary box center point and a secondary box radius and a secondarypin shoulder with a fourth curved profile defined by a secondary axialpin radius height, a secondary pin center point and a secondary pinradius. In an embodiment, the secondary box shoulder contacts thesecondary pin shoulder to form a torque shoulder.

In an embodiment, the second end is offset a first distance from thefirst end. In an embodiment, the first distance is from about 1 inch toabout 8 inches. In an embodiment, the first distance is from about 2inches to about 8 inches. In an embodiment, the first distance is aconnection length.

In an embodiment, the secondary axial box radius height is from about0.000 inch to about the length of the secondary box radius in inches;and the secondary axial pin radius height is from about 0.000 inch toabout the length of the secondary pin radius in inches.

In an embodiment, the secondary box center point is located at abouthalf-way between a pin nose outer diameter and a pin nose innerdiameter; and the secondary pin center point is located at abouthalf-way between the pin nose outer diameter and the pin nose innerdiameter.

In an embodiment, the secondary box radius is greater than about [(pinnose outer diameter−pin nose inner diameter)/4] inches; and thesecondary pin radius is greater than about [(pin nose outer diameter−pinnose inner diameter)/4] inches. In an embodiment, the secondary boxradius is about equal to the secondary pin radius to form the torqueshoulder. In an embodiment, the secondary box radius is slightlydifferent than the secondary pin radius to form the torque shoulder.

In an embodiment, the secondary box shoulder is concave shaped and thesecondary pin shoulder is convex shaped.

In an embodiment, the secondary box shoulder has one or more of a fourthflat region at an inner edge of the second curved profile and a fifthflat region at an outer edge of the second curved profile; and thesecondary pin shoulder has one or more of a sixth flat region at aninner edge of the second curved profile and a second angled region at anouter edge of the second curved profile.

In an embodiment, the rotary shoulder connection further comprises: asecondary shoulder connection at a second end of the box connection anda second end of the pin connection. In an embodiment, the secondaryshoulder connection comprises: a secondary box shoulder at a secondarybox angle with respect to a second perpendicular to the box axis at asecond end point and a secondary pin shoulder at a secondary pin anglewith respect to the second perpendicular to the pin axis at the secondend point. In an embodiment, the secondary box shoulder contacts thesecondary pin shoulder to form a torque shoulder.

In an embodiment, the second end is offset a first distance from thefirst end. In an embodiment, the first distance is from about 1 inch toabout 8 inches. In an embodiment, the first distance is from about 2inches to about 8 inches. In an embodiment, the first distance is aconnection length.

In an embodiment, the secondary box angle is from greater than or equalto about 0 degrees to less than or equal to 15 degrees; and thesecondary pin angle is from greater than or equal to about 0 degrees toless than or equal to 15 degrees. In an embodiment, the secondary boxangle is from greater than or equal to about 0 degrees to less than orequal to 10 degrees; and the secondary pin angle is from greater than orequal to about 0 degrees to less than or equal to 10 degrees. In anembodiment, the secondary box angle is about 5 degrees; and thesecondary pin angle is about 5 degrees. In an embodiment, the secondarybox angle is about 0 degrees; and the secondary pin angle is about 0degrees.

In an embodiment, the secondary box angle is about equal to thesecondary pin angle to form the torque shoulder. In an embodiment, thesecondary box angle is slightly different than the secondary pin angleto form the torque shoulder.

In an embodiment, the secondary box shoulder is conical shaped (outsideof cone, male) and the secondary pin shoulder is conical shaped (insideof cone, female).

In an embodiment, the box thread form comprises a first box threadcrest, a second box thread crest, a first box thread flank, a second boxthread flank, a box included angle between the first box thread flankand the second box thread flank, and a box thread root, and wherein thepin thread form comprises a first pin thread crest, a second pin threadcrest, a first pin thread flank, a second pin thread flank, a pinincluded angle between the first pin thread flank and the second pinthread flank, and a pin thread root.

In an embodiment, the box thread form is selected from the groupconsisting of square, triangular, trapezoidal, and variations thereof,and the pin thread form is selected from the group consisting of square,triangular, trapezoidal, and variations thereof.

In an embodiment, the first box thread crest and/or the second boxthread crest is circular, square, triangular or trapezoidal shaped; andfirst pin thread crest and/or the second pin thread crest is circular,square, triangular or trapezoidal shaped.

In an embodiment, the first box thread flank and/or the second boxthread flank are concave, convex, or straight shaped, and wherein thefirst pin thread flank and/or the second pin thread flank are concave,convex, or straight shaped.

In an embodiment, the box thread root is circular, square, triangular ortrapezoidal shaped, and wherein the pin thread root is circular, square,triangular or trapezoidal shaped.

In an embodiment, the box included angle is from about 29 degrees toabout 90 degrees, and the pin included angle is from about 29 degrees toabout 90 degrees. In an embodiment, the box thread form is triangularand the box included angle is about 60 degrees, and the pin thread formis triangular shaped and the pin included angle is about 60 degrees.

In an embodiment, the box threads and/or the pin threads are treated byone or more of cold rolling, shot peening, phosphating, fluoropolymercoating, ceramic coating, chrome plating, anodizing, and variationsthereof. In an embodiment, the box threads and/or the pin threads aretreated by one or more of cold rolling, shot peening, fluoropolymercoating, and anodizing.

In an embodiment, the rotary shoulder connection further comprises oneor more of a box boreback, a box stress relief groove and a pin stressrelief groove.

In an embodiment, the rotary shoulder connection is made from one ormore of low alloy steels, stainless steels, super alloys, titaniumalloys, copper alloys, cobalt alloys, aluminum alloys, and variationsthereof. In an embodiment, the rotary shoulder connection is made fromone or more of low alloy steels, stainless steels, and variationsthereof.

In an embodiment, the rotary shoulder connection is applied to one ormore of drill pipe, heavy weight drill pipe, drill collars, pup joints,crossover subs, saver subs, bit subs, float subs, pump-in subs, insideblowout preventers, top drive shafts, top drive valves, safety valves,kelly valves, hoisting equipment, swivels, fishing tools, mud motors,rotary steerable tools, drill bits, directional drilling bottom holeassembly components, measurement while drilling components, loggingwhile drilling components, well cleanout tools, completion tools, andvariations thereof.

In an embodiment, the rotary shoulder connection is applied to one ormore of drill pipe, heavy weight drill pipe, drill collars, pup joints,and variations thereof.

In an embodiment, a method of using a rotary shoulder connectioncomprises: providing the rotary shoulder connection; and applying therotary shoulder connection to one or more products. In an embodiment,the rotary shoulder connection may be the improved double shoulderconnection with a curved primary shoulder or the improvedsingle-shoulder connection with a curved primary shoulder, as discussedabove.

In an embodiment, the method further comprises tightening the rotaryshoulder connection between one of more products to form the first seal.

In an embodiment, the method further comprises tightening the rotaryshoulder connection between the one or more products to form the firstseal and the torque shoulder.

In an embodiment, a method for determining a primary shoulder locationcomprises: locating a pitch line parallel to a connection box/pin taper;locating a first intersection of a pitch diameter and the pitch line;locating a first perpendicular to the connection box/pin axis at thefirst intersection; locating a second perpendicular to the connectionbox/pin axis at a first distance towards a primary box/pin shoulder fromthe first perpendicular; locating a first reference plane, and,optionally, locating a second intersection of the pitch line and thesecond perpendicular; and selecting a primary axial box/pin radiusheight, selecting a primary box/pin radius, and locating a primarybox/pin center point between a box counter bore diameter and a pin beveldiameter.

In an embodiment, the method for determining a primary shoulder locationfurther comprises step (g) defining a primary box/pin curved profilewith respect to primary axial box/pin radius height, the primary box/pincenter point and the primary box/pin radius, and, optionally, defining aprimary box/pin angle with respect to the second perpendicular at thesecond intersection.

In an embodiment, the method for determining a primary shoulder locationfurther comprises step (f) defining a primary box/pin angle with respectto the second perpendicular at the second intersection.

In an embodiment, the first distance is from about 0.5 inch to about2.50 inches. In an embodiment, the first distance is from about 0.625inch to about 2.250 inches. In an embodiment, the first distance isabout 0.625 inch.

In an embodiment, a method for determining a secondary shoulderconnection location comprises: locating a pitch line parallel to aconnection box/pin taper; locating a first intersection of a pitchdiameter and the pitch line; locating a first perpendicular to theconnection box/pin axis at the first intersection; locating a secondperpendicular to the connection box/pin axis at a first distance towardsa primary box/pin shoulder from the first perpendicular; locating afirst reference plane, and, optionally, locating a second intersectionof the pitch line and the second perpendicular; locating a thirdperpendicular to the connection box/pin axis at a second distance towarda secondary box/pin shoulder; locating a second reference plane, and,optionally, locating a third intersection of a pin nose outer diameterand the third perpendicular; and selecting a secondary axial box/pinradius height, selecting a secondary box/pin radius, and locating asecondary box/pin center point between a pin nose outer diameter and apin nose inner diameter.

In an embodiment, a method for determining a secondary shoulderconnection location further comprises defining a secondary box/pincurved profile with respect to secondary axial box/pin radius height,the secondary box/pin center point and the secondary box/pin radius,and, optionally, defining a secondary box/pin angle with respect to thethird perpendicular at the third intersection.

In an embodiment, a method for determining a secondary shoulderconnection location further comprises optionally, defining a primarybox/pin angle with respect to the second perpendicular at the secondintersection.

In an embodiment, a method for determining a secondary shoulderconnection location further comprises optionally, defining a secondarybox/pin angle with respect to the third perpendicular at the thirdintersection.

In an embodiment, the second distance is from about 1 inch to about 8inches. In an embodiment, the second distance is from about 2 inches toabout 8 inches. In an embodiment, the second distance is a connectionlength.

In an embodiment, a drill pipe comprises a drill pipe body having adrill pipe body outer diameter and a drill pipe body inner diameter; anda tool joint comprising a rotary shoulder box connection; wherein thedrill pipe has an optimization ratio (Ro) defined by

${{Ro} = \frac{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}\mspace{14mu} {strength}}{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}{\; \mspace{11mu}}{pressure}\mspace{14mu} {loss}}},$

andwherein the optimization ratio is at least about 0.68 for a productionhole from about 7⅞-inches to about 12¼-inches.

In an embodiment, a drill pipe comprises a drill pipe body having adrill pipe body outer diameter and a drill pipe body inner diameter,wherein the drill pipe body outer diameter is from about 5.1-inches toabout 5.4-inches and the drill pipe body inner diameter is from about4.4-inches to about 4.6-inches; and a tool joint comprising a rotaryshoulder box connection; wherein the drill pipe has an optimizationratio (Ro) defined by

${{Ro} = \frac{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}\mspace{14mu} {strength}}{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}\mspace{14mu} {pressure}\mspace{14mu} {loss}}},$

andwherein the optimization ratio is at least about 0.68 for a productionhole from about 7⅞-inches to about 12¼-inches.

In an embodiment, the optimization ratio is approximated by

${Ro} = {\frac{{Pod} - {Pid}}{{EQod} - {EQid}}.}$

In an embodiment, the optimization ratio is at least about 0.68 for aproduction hole of about 7⅞-inches. In an embodiment, the optimizationratio is at least about 0.70 for a production hole of about 8½-inches.In an embodiment, the optimization ratio is at least about 0.62 for aproduction hole of about 12¼-inches.

In an embodiment, the optimization ratio is at least about 0.68 for aproduction hole of about 7⅞-inches at a flow rate of 600 gpm. In anembodiment, the optimization ratio is at least about 0.70 for aproduction hole of about 8½-inches at a flow rate of about 600 gpm. Inan embodiment, the optimization ratio is at least about 0.62 for aproduction hole of about 12¼-inches at a flow rate of about 900 gpm.

In an embodiment, the optimization ratio is at least about 0.68 for aproduction hole of about 7⅞-inches at a flow rate of 600 gpm of 12 poundper gallon mud. In an embodiment, the optimization ratio is at leastabout 0.70 for a production hole of about 8½-inches at a flow rate ofabout 600 gpm of 12 pound per gallon mud. In an embodiment, theoptimization ratio is at least about 0.62 for a production hole of about12¼-inches at a flow rate of about 900 gpm of 12 pound per gallon mud.

In an embodiment, the drill pipe body outer diameter is from about5.1-inches to about 5.4-inches and the drill pipe body inner diameter isfrom about 4.4-inches to about 4.6-inches. In an embodiment, the drillpipe body outer diameter is about 5.25-inches and the drill pipe bodyinner diameter is about 4.528-inches.

In an embodiment, the drill pipe body comprises a drill pipe body wallthickness, wherein the drill pipe body wall thickness is from about0.352-inches to about 0.370-inches. In an embodiment, the drill pipebody wall thickness is about 0.361-inch.

In an embodiment, the drill pipe comprises a drill pipe length, whereinthe drill pipe length is from about 25-feet to about 50-feet. In anembodiment, the drill pipe length is about 31.5-feet.

In an embodiment, the rotary shoulder connection comprises a rotaryshoulder connection length, wherein the rotary shoulder connectionlength is from about 4.275-inches to about 5.225-inches. In anembodiment, the rotary shoulder connection length is about 4.75-inches.

In an embodiment, a method of using a drill pipe comprises providing aplurality of the drill pipe as discussed herein; and connecting theplurality of the drill pipe to produce a drill string.

These and other objects, features and advantages will become apparent asreference is made to the following detailed description, preferredembodiments, and examples, given for the purpose of disclosure, andtaken in conjunction with the accompanying drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the U.S. Patent and TrademarkOffice upon request and payment of a required fee.

For a further understanding of the nature and objects of the presentinvention, reference should be made to the following detaileddisclosure, taken in conjunction with the accompanying drawings, inwhich like parts are given like reference numerals, and wherein:

FIG. 1A illustrates a partial cross-sectional view of a double-shoulderconnection with a pin and box made-up (screwed together), showing boxconnection features;

FIG. 1B illustrates the double-shoulder connection of FIG. 1A, showingpin connection features;

FIG. 2A illustrates a cross-sectional view of a standard (typical)double-shoulder connection, showing a standard primary shoulderconnection and a standard secondary shoulder connection;

FIG. 2B illustrates a detailed view C1 in FIG. 2A, showing the standardprimary shoulder connection;

FIG. 2C illustrates a detailed view C2 in FIG. 2A, showing the standardsecondary shoulder connection;

FIG. 3A illustrates a cross-sectional view of the standard (typical)double shoulder connection shown in FIG. 2A, showing an exaggerateddeformation of the box connection and the pin connection for claritypurposes;

FIG. 3B illustrates a detailed view D in FIG. 3A, showing a threadmisalignment;

FIG. 4A illustrates a cross-sectional view of an improveddouble-shoulder connection with an angled primary shoulder and astandard secondary shoulder according to an embodiment of the presentinvention;

FIG. 4B illustrates a detailed view E in FIG. 4A, showing the angledprimary shoulder according to an embodiment of the present invention;

FIG. 5A illustrates a cross-sectional view of the improveddouble-shoulder connection of FIG. 4A, showing box radial retainingforces and pin radial retaining forces;

FIG. 5B illustrates a detailed view F in FIG. 5A, showing improvedthread alignment;

FIG. 6A illustrates a cross-sectional view of an improveddouble-shoulder connection with a standard primary shoulder and anangled secondary shoulder according to an embodiment of the presentinvention, showing box radial retaining forces and pin radial retainingforces;

FIG. 6B illustrates a detailed view G in FIG. 6A, showing the angledsecondary shoulder according to an embodiment of the present invention;

FIG. 7 illustrates a cross-sectional view of an improved double-shoulderconnection with an angled primary shoulder and an angled secondaryshoulder according to an embodiment of the present invention;

FIG. 8A illustrates a cross-sectional view of an improvedsingle-shoulder connection with an angled primary shoulder according toan embodiment of the present invention;

FIG. 8B illustrates a detailed view H in FIG. 8A, showing the angledprimary shoulder according to an embodiment of the present invention;

FIG. 9 illustrates a cross-sectional view of an improved single-shoulderconnection with box and pin stress relief grooves according to anembodiment of the present invention;

FIG. 10 illustrates a cross-sectional view of an improvedsingle-shoulder connection with a box boreback and a pin stress reliefgroove according to an embodiment of the present invention;

FIG. 11 illustrates a cross-sectional detailed view of a thread formaccording to an embodiment of the present invention;

FIG. 12 illustrates a cross-sectional view of an improved primaryconnection shoulder according to an embodiment of the present invention;

FIG. 13 illustrates a flow chart of a method for determining a primaryconnection shoulder location according to an embodiment of the presentinvention;

FIG. 14 illustrates a cross-sectional view of an improved secondaryconnection shoulder according to an embodiment of the present invention;

FIG. 15 illustrates a flowchart of a method for determining a secondaryconnection shoulder location according to an embodiment of the presentinvention;

FIG. 16 illustrates a flowchart of a method of using an improveddouble-shoulder connection with an angled primary shoulder or animproved single-shoulder connection with an angled primary shoulderaccording to an embodiment of the present invention;

FIG. 17A illustrates a cross-sectional view of an improveddouble-shoulder connection with a curved primary shoulder and a standardsecondary shoulder according to an embodiment of the present invention;

FIG. 17B illustrates a detailed view E in FIG. 17A, showing the curvedprimary shoulder according to an embodiment of the present invention;

FIG. 18A illustrates a cross-sectional view of the improveddouble-shoulder connection of FIG. 17A, showing box radial retainingforces and pin radial retaining forces;

FIG. 18B illustrates a detailed view F in FIG. 18A, showing improvedthread alignment;

FIG. 19A illustrates a cross-sectional view of an improveddouble-shoulder connection with a standard primary shoulder and a curvedsecondary shoulder according to an embodiment of the present invention,showing box radial retaining forces and pin radial retaining forces;

FIG. 19B illustrates a detailed view G in FIG. 19A, showing the curvedsecondary shoulder according to an embodiment of the present invention;

FIG. 20 illustrates a cross-sectional view of an improveddouble-shoulder connection with an a curved primary shoulder and acurved secondary shoulder according to an embodiment of the presentinvention;

FIG. 21A illustrates a cross-sectional view of an improvedsingle-shoulder connection with a curved primary shoulder according toan embodiment of the present invention;

FIG. 21B illustrates a detailed view H in FIG. 21A, showing the curvedprimary shoulder according to an embodiment of the present invention;

FIG. 22 illustrates a cross-sectional view of an improvedsingle-shoulder connection with box and pin stress relief groovesaccording to an embodiment of the present invention;

FIG. 23 illustrates a cross-sectional view of an improvedsingle-shoulder connection with a box boreback and a pin stress reliefgroove according to an embodiment of the present invention;

FIG. 24A illustrates a cross-sectional view of an improved double- orsingle-shoulder connection with a curved primary connection shoulderaccording to an embodiment of the present invention;

FIG. 24B-1 illustrates a detailed view of the double- or single-shoulderconnection in FIG. 24A, showing the curved primary connection shoulderaccording to an embodiment of the present invention;

FIG. 24B-2 illustrates an enlarged detailed view of the double- orsingle-shoulder connection in FIG. 24B-1, showing the curved primaryconnection shoulder according to an embodiment of the present invention;

FIG. 24C illustrates a cross-sectional view of an improved double- orsingle shoulder connection with an angled primary connection shoulderaccording to an embodiment of the present invention;

FIG. 25 illustrates a flow chart of a method for determining a primaryconnection shoulder location according to an embodiment of the presentinvention;

FIG. 26A illustrates a cross-sectional view of an improveddouble-shoulder connection with a curved primary connection shoulder anda curved secondary connection shoulder according to an embodiment of thepresent invention;

FIG. 26B-1 illustrates a detailed view of the double-shoulder connectionin FIG. 26A, showing the curved secondary connection shoulder accordingto an embodiment of the present invention;

FIG. 26B-2 illustrates an enlarged detailed view of the double-shoulderconnection in FIG. 26B-1, showing the curved secondary connectionshoulder according to an embodiment of the present invention;

FIG. 26C illustrates a cross-sectional view of an improveddouble-shoulder connection with a standard primary connection shoulderand an angled secondary connection shoulder according to an embodimentof the present inventions;

FIG. 27 illustrates a flow chart of a method for determining a secondaryconnection shoulder location according to an embodiment of the presentinventions; and

FIG. 28 illustrates a flowchart of a method of using an improveddouble-shoulder connection with a curved primary connection shoulder oran improved single-shoulder connection with a curved primary connectionshoulder according to an embodiment of the present invention;

FIG. 29 illustrates an exemplary wellbore diagram;

FIG. 30 illustrates a chart of hole size (inches) vs. Fc—CriticalBuckling Load (lbs) for an embodiment of the present invention (e.g.,5¼-inches drill pipe), showing sinusoidal drill pipe buckling straight,inclined well bores;

FIG. 31 illustrates a chart of hole size (inches) vs. Fc—CriticalBuckling Load (lbs) for a standard API 5-inch drill pipe, showingsinusoidal drill pipe buckling straight, inclined well bores;

FIG. 32 illustrates a chart of hole size (inches) vs. Fc—CriticalBuckling Load (lbs) for a standard API 5½-inch drill pipe, showingsinusoidal drill pipe buckling straight, inclined well bores;

FIG. 33 illustrates a chart of tool joint outer diameter (OD) (inches)vs. capacity (lbs) for an embodiment of the present invention (e.g.,5¼-inches drill pipe), showing elevator carrying capacity;

FIG. 34A illustrates cross-sectional view of a drill pipe according toan embodiment of the present invention, showing a double-shoulderconnection with a box connection at one end and a pin connection at theother; and

FIG. 34B illustrates cross-sectional view of a drill pipe according toan embodiment of the present invention, showing a double-shoulderconnection with a box connection at one end and a pin connection at theother.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The following detailed description of various embodiments of the presentinvention references the accompanying drawings, which illustratespecific embodiments in which the invention can be practiced. While theillustrative embodiments of the invention have been described withparticularity, it will be understood that various other modificationswill be apparent to and can be readily made by those skilled in the artwithout departing from the spirit and scope of the invention.Accordingly, it is not intended that the scope of the claims appendedhereto be limited to the examples and descriptions set forth herein butrather that the claims be construed as encompassing all the features ofpatentable novelty which reside in the present invention, including allfeatures which would be treated as equivalents thereof by those skilledin the art to which the invention pertains. Therefore, the scope of thepresent invention is defined only by the appended claims, along with thefull scope of equivalents to which such claims are entitled

Standard (Typical) Drill Pipe

Standard (typical) drill pipe is typically based on American PetroleumInstitute (API) design methodology and specifications. Such drill pipeis commercially available in API 2⅜-inches, API 2⅞-inches, API3½-inches, API 4-inches, API 4½-inches, API 5-inches, API 5½-inches andAPI 6⅝-inches sizes. Typical API casing sizes, of mixed walls andweights, range from 4½-inches to 13⅝-inches.

For drilling a given hole or bit size, a proper design of a drill stringand/or drill pipe is critical for achieving hole cleaning objectives,desired hole geometry and trajectory in a specific application. Forexample, an annulus (i.e., area between the drill string and the hole)can create problems if too large or small. If the annulus is too large,an inadequate hole cleaning may occur. If the annulus is too small, highfriction pressures and turbulent erosion can occur.

Drill Pipe Design Considerations

A proper design of the drill string or drill pipe (i.e., grade, size andweight) is based on a number of factors including, but not limited to,component availability, component cost, component size, materialrequirements, and strength requirements, as discussed below.

Strength Requirements

The drill string and/or drill pipe must be strong enough to handle theservice loads during all phases of the drilling program, including:

-   1. Torsion and tension loads when rotating the drill pipe (rotary    torque) and when pulling the drill pipe out of the hole (POOH);    and/or-   2. Compressive and bending loads when the drill pipe is in a dogleg    and when advancing the drill bit in horizontal sections of the hole.    There are also pressure requirements, internal and external, from    the flow of fluid inside the drill pipe and from drill stem testing.    In most, if not all, cases, the drill pipe may be subjected to a    combination of all of these loads.

With respect to design of the drill string and/or drill pipe, thestrength of each member must be evaluated in terms of the forces andloads it will encounter under static, dynamic and fatigue conditions.The API design methodology for drill pipe assumes the outside diameterof the box tool joint and inside diameter of the pin tool jointconfigure in such a manner that the connection-to-tube torsionalstrength ratio calculates to 0.8 or greater.

This API guideline leaves much to be desired because this ratiodecreases as wall thickness increases or as tube grade (material yieldstrength) increases. Further, changes in the OD and ID of the tooljoints can result in lower drill pipe torsion-strength ratios,potentially rendering the drill pipe unsuitable for a specificapplication.

For many high-strength G-105 grade and S-135 grade drill pipeassemblies, the tool joint ID must be quite small to increase thetorsional strength of the connection such that substantial restrictionsfor hydraulic and drill stem logging and directional tools are created.The standard API 5-inch S-135 grade drill pipe with NC50 connections istorque limited with a tool joint-to-new pipe torsional strength ratio of0.75 on 19.50 ppf (i.e., 0.362-inch wall thickness) S-135 grade drillpipe.

In contrast, the presented invention (e.g., 5¼-inches drill pipeassembly) optionally features a 130 ksi SMYS (6¼-inches OD×3½-inches ID)EVRDRL49G, double-shoulder connection (i.e., tool joint) with animproved tool joint-to-pipe body torsional ratio compared to a standardAPI single-shoulder connection drill pipe. For a 5¼-inches, 20.70 ppf(i.e., 0.361-inch wall thickness), S-135 grade drill pipe, the tooljoint-to-pipe torsional ratio is 85%.

Table 1 permits comparison of the present invention (e.g., 5¼-inchesdrill pipe assembly) to the standard API 5-inches and API 5½-inchesdrill pipe assemblies of the same wall thickness (i.e., 0.362-inch).

TABLE 1 Drill Tool Tool Tool Drill Pipe Tool Joint Joint Joint RSC DrillPipe Weld Joint Pin ID Pin OD Box OD Bevel Approx. Designations PipeWall Neck OD (in.) Length Length Dia. Mass Upset RSC OD (in.) (in.)(in.) +0.016 + (in.) (in.) (in.) (lb/ft.) Label 1 Label 2 Grade TypeType (in.) −12.5% Max ±0.031 0.031 ±0.250 ±0.250 ±0.016 Calc. 1 2 3 4 56 7 8 9 10 11 12 13 14 5 19.50 E IEU NC50 5.000 0.362 5.125 6.625 3.7507.000 10.000 6.063 21.37 5 19.50 X IEU NC50 5.000 0.362 5.125 6.6253.500 7.000 10.000 6.063 21.89 5 19.50 G IEU NC50 5.000 0.362 5.1256.625 3.250 7.000 10.000 6.063 22.14 5 19.50 S IEU NC50 5.000 0.3625.125 6.625 2.750 7.000 10.000 6.063 22.58 5 19.50 E IEU 5½ FH 5.0000.362 5.125 7.000 3.750 8.000 10.000 6.719 22.32 5 19.50 X, G IEU 5½ FH5.000 0.362 5.125 7.000 3.750 8.000 10.000 6.719 22.58 5 19.50 S IEU 5½FH 5.000 0.362 5.125 7.250 3.500 8.000 10.000 6.719 23.44 5 25.60 E IEUNC50 5.000 0.500 5.125 6.625 3.500 7.000 10.000 6.063 27.37 5 25.60 XIEU NC50 5.000 0.500 5.125 6.625 3.000 7.000 10.000 6.063 28.09 5 25.60G IEU NC50 5.000 0.500 5.125 6.625 2.750 7.000 10.000 6.063 28.30 525.60 E IEU 5½ FH 5.000 0.500 5.125 7.000 3.500 8.000 10.000 6.719 28.325 25.60 X IEU 5½ FH 5.000 0.500 5.125 7.000 3.500 8.000 10.000 6.71928.56 5 25.60 G IEU 5½ FH 5.000 0.500 5.125 7.250 3.500 8.000 10.0006.719 29.13 5 25.60 S IEU 5½ FH 5.000 0.500 5.125 7.250 3.250 8.00010.000 6.719 29.40 5½ 21.90 E IEU 5½ FH 5.500 0.361 5.688 7.000 4.0008.000 10.000 6.719 23.81 5½ 21.90 X IEU 5½ FH 5.500 0.361 5.688 7.0003.750 8.000 10.000 6.719 24.43 5½ 21.90 G IEU 5½ FH 5.500 0.361 5.6887.250 3.500 8.000 10.000 6.719 25.28 5½ 21.90 S IEU 5½ FH 5.500 0.3615.688 7.500 3.000 8.000 10.000 7.094 26.39

Component Size

In the design of the drill string and/or drill pipe, component size ofthe drill pipe body and the tool joint must be considered in relation tothe hole diameter. For a given drill pipe and hole diameter, there areseveral hydraulic consequences of this relationship. Of these, theannular velocity (AV) and equivalent circulation density (ECD) are themost significant. As drill pipe size increases in relation to the hole,the pump flow needed to attain the AV required for drill bit cuttingstransport decreases. However, the ECD increases because it takes morepressure to pump the mud past the drill pipe and to the surface.

To properly design the drill string and/or drill pipe, the AV and ECDmust be balanced for the specific application. A higher AV may beachieved with the larger drill pipe size, but a lower ECD becomes amajor consideration for long and building angle, or deviated, holes.

Improved Hydraulic Efficiency

The present invention (e.g., 5¼-inches drill pipe with EVRDRL49Gdouble-shoulder connections) has an improved hydraulic efficiency overthe standard API 5-inches pipe due to a larger tube and tool joint borediameters. Further, the present invention (e.g., 5¼-inches drill pipewith EVRDRL49G double-shoulder connections) provides a lower ECD thanthe standard API 5½-inches drill pipe due to a smaller pipe OD.

Tables 2-4 provide an equivalent pipe inside diameter, the ECD and acalculated pressure loss per 1000 feet for the standard API 5-inchesdrill pipe, the present invention (e.g., 5¼-inches drill pipe) andstandard API 5½-inches drill pipe, based on maximum achievable BHA flowrates for the 12¼-inches (900 gpm), 8½-inches (600 gpm—limited by motor)and 7⅞-inches hole sizes (600 gpm—limited by motor).

TABLE 2 Equivalent Diameter (in.) Flow Rate Flow Rate Capacity of DrillPipe (600 gpm) (9900 gpm) (gal/ft) 5-inch, 19.50# (0.362- 3.75 3.640.716 inch wall) Drill Pipe with 6.625-inch × 3.25-inch Tool Joints5¼-inch, 20.70# 4.04 3.95 0.784 (0.361-inch wall) Drill Pipe with 6.25-inch × 3.5-inch Tool Joints 5½-inch, 21.90# 4.15 4.01 0.890 (0.361-inchwall) Drill Pipe with 7.25- inch × 3.5-inch Tool Joints

TABLE 3 Equivalent Circulation Density (lb/gal) Flow Rate Flow Rate FlowRate (600 gpm) (600 gpm) (900 gpm) 5-inch, 19.50# (0.362- 14.41 14 17.50inch wall) Drill Pipe with 6.625-inch × 3.25-inch Tool Joints 5¼-inch,20.70# 13.92 13.78 15.98 (0.361-inch wall) Drill Pipe with 6.25- inch ×3.5-inch Tool Joints 5½-inch, 21.90# 16.45 14.09 25.60 (0.361-inch wall)Drill Pipe with 7.25- inch × 3.5-inch Tool Joints

TABLE 4 Pressure Loss per 1000 feet of Drill Pipe Hole Size Hole SizeHole Size (7⅞-inch) (8½-inch) (12¼-inch) Flow Rate Flow Rate Flow Rate12 lb/gal mud (600 gpm) (600 gpm) (900 gpm) 5-inch, 19.50# 266 242 483(0.362-inch wall) Drill Pipe 5¼-inch, 20.70# 207 185 343 (0.361-inchwall) Drill Pipe 5½-inch, 21.90# 252 171 300 (0.361-inch wall) DrillPipe Annular Annular Annular Velocity Velocity Velocity (600 gpm) (600gpm) (900 gpm)

For a 12¼-inches hole, the present invention (e.g., 5¼-inches drillpipe) provides a 9.5% increase in capacity over the standard API5-inches drill pipe, decreasing a combined (bore and annulus) pressurelosses by 29% per 1000 feet of drill pipe in the 12¼-inches hole whenconsidering 12 lb/gal mud and a 900 gpm flow rate.

Similarly, for a 7⅞-inches hole, the annulus pressure loss for thepresent invention (e.g., 5¼-inches drill pipe) was 13.6% lower than thestandard API 5-inches pipe, decreasing the bore pressure loss by a 35.8%per 1000 feet of drill pipe in the 7⅞-inches hole when considering 12lb/gal mud and a 600 gpm flow rate.

Improved Buckling Strength

The present invention (e.g., 5¼-inches drill pipe with EVRDRL49Gdouble-shoulder connections) has an improved bucking strength over thestandard API 5-inches pipe due a relationship between the drill pipesize and hole size. See Table 5 below.

TABLE 5 Critical Buckling Load of 5-inch and 5¼-inch Drill Pipe in7⅞-inch Diameter Hole¹ Deviation 30-Degrees 60-Degrees 90-Degress5-inch, 19.50# (0.362- 31221 lbs 41089 lbs 44153 lbs inch wall), IEUS-135 Drill Pipe 5¼-inch, 20.70# 34585 lbs 45516 lbs 48910 lbs(0.361-inch wall), IEU S-135 Drill Pipe ¹Buckling loads calculated usingweight of drill pipe in air.

FIG. 30 illustrates a chart of hole size (inches) vs. Fc—CriticalBuckling Load (lbs) for an embodiment of the present invention (e.g.,5¼-inches drill pipe), showing sinusoidal drill pipe buckling straight,inclined well bores; FIG. 31 illustrates a chart of hole size (inches)vs. Fc—Critical Buckling Load (lbs) for a standard API 5-inches drillpipe, showing sinusoidal drill pipe buckling straight, inclined wellbores; and FIG. 32 illustrates a chart of hole size (inches) vs.Fc—Critical Buckling Load (lbs) for a standard API 5½-inches drill pipe,showing sinusoidal drill pipe buckling straight, inclined well bores.

The larger the drill pipe in a given hole size, the higher the criticalbuckling load. Buckling and rotating of the drill pipe at the same timecan cause rapid fatigue failure. If the drill string undergoesmechanical compression that exceeds its critical buckling load, thestring will first buckle sinusoidally. That is, the drill stringabruptly assumes a snaked, or sinusoidal shape in the wellbore. Ifcompression continues to increase, the drill string will finally achievea helical shape in the wellbore. Rotary-mode buckling is unavoidable invertical hole sections. This occurs because the long elastic drillstring, sometimes reaching lengths in excess of 4 miles, has very littlestability unless it is pressed against the side of the hole over somesignificant length. Forces which accomplish this are absent in astraight, vertical hole. Once the hole angle deviates a few degrees fromvertical, or if the hole is curving upward, the drill string gainsstability and can carry higher compressive loads and remain stable. Forthe drill pipe size with the higher buckling resistance, the more weightcan be applied to the bit, increasing penetration rates and lesseningfatigue damage in directional holes. This consideration favors thelargest possible drill pipe tube size for a given hole.

In a high angle ER well, drill bit weight cannot be efficiently appliedwith the traditional BHA, and it becomes necessary to mechanicallycompress the normal weight drill pipe to apply the drill bit weight.Because of the high hole angles, it's often necessary while rotating toapply drill bit weight with normal weight drill pipe (NWDP) run inmechanical compression. However, so long as the drill pipe is notbuckled, no significant fatigue damage should be expected.

In sliding mode drilling, hole friction may cause drill pipe bucklingwhen attempting to apply weight on the drill bit. In the absence ofrotation however, no significant fatigue damage is likely. Fortunately,high hole angles help stabilize the drill pipe and allows for a certainamount of mechanical compression. So long as the magnitude of mechanicalcompression does not exceed the critical buckling load, the drill piperemains stable. When drilling the horizontal section of the hole, thedrill bit weight is applied by mechanically compressing the drill pipein the build zone. Above the kickoff point in the vertical section ofthe hole, buckling is predicted as soon as the drill pipe goes intomechanical compression regardless of drill pipe size or hole size. Thus,the available drill bit weight will be a function of the drill pipeweight in the build zone and horizontal section.

The buckling strength calculated using the Dawson Paslay formula showsthe present invention (e.g., 5¼-inches drill pipe) buckling resistance(i.e., stiffness) to be approximately 10% higher than the 5-inches drillpipe while the present invention (e.g., 5¼-inches drill pipe) is onlyabout 0.8% heavier than the 5-inches drill pipe (weights adjusted toinclude tool joints).

As shown in FIG. 30, nearly 50,000 lbf can be applied to the presentinvention (e.g., 5¼-inches drill pipe), inside a 7⅞-inches hole withlittle to no buckling anywhere in the horizontal section.

Improved Elevator Hoist Capacity

The present invention (e.g., 5¼-inches drill pipe with EVRDRL49Gdouble-shoulder connections) has an improved elevator hoist capacityover the standard API 5½-inches drill pipe due to the size of the tooljoint in relation to the drill pipe.

A maximum drill pipe elevator hoist capacity is a function of a contactarea between an elevator and a tool joint elevator shoulder, which isdependent on the difference between the tool joint OD and the drill pipeOD adjacent to the tool joint. The smaller the tool joint OD relative tothe drill pipe OD, the lower the elevator hoist capacity.

The elevator hoist capacities for the present invention (e.g., 5¼-inchesdrill pipe) and the standard API 5½-inches drill pipe were calculatedbased on a projected area of the elevator contact surface (i.e., bowlbore), using a 100,000-psi contact stress. See Table 6.

TABLE 6 Elevator Hoist Capabilities New Nominal Elevator Tool Max. Tube(100% RBW) Carrying Drill Pipe Joint Upset OD Tube Tensile Capacity¹Assembly OD (in.) (in.) Strength (lbs) (lbs) 5-inch IEU 6¼ 5⅛ 712100994432 S-135 Drill Pipe 5¼-inch IEU 6¼ 5⅜ 748500 762037 S-135 Drill Pipe5½-inch IEU 6¼ 5 11/16 786800 424846 S-135 Drill Pipe ¹Based on 100,000psi contact stress and 1/32-inch elevator wear factor.

FIG. 33 illustrates a chart of tool joint outer diameter (OD) (inches)vs. capacity (lbs) for an embodiment of the present invention (e.g.,5¼-inches drill pipe), showing elevator hoist capacity.

Improved Drill String Fishability

The present invention (e.g., 5¼-inches drill pipe with EVRDRL49Gdouble-shoulder connections) has an improved drill string fishabilityover the standard API 5-inches drill pipe due to the tool joint OD inrelation to hole size. See Table 7.

For the present invention (e.g., 5¼-inches drill string) that has becomeseparated or unscrewed downhole, conventional high-strength fishingtools are readily available to aid in recovering the separated orunscrewed drill string (fish) and allowing drilling to continue.

In relation to a typical well design, a 9⅝-inches 53.50 ppf casingproduces an 8½-inches holes, with enough annular ID clearance forfishing equipment (overshot) sizes up to 8⅜-inches OD and capable ofcatching tool joints up to 7¼-inches OD.

Similarly, an 8⅝-inches casing produces a 7⅞-inches holes for 7¾-inchesOD overshot to catch tool joints 6⅜-inches OD.

For a standard API 5-inch NC50 tool joint, drill string fishability islimited by the tool joint OD as it relates to hole size. The standardAPI 5-inches drill pipe has limited-to-no fishability by way of overshotin a 7⅞-inches hole with an 8⅝-inches or 8¾-inches casing due to a6⅝-inches OD NC50 tool joint. For the 7⅞-inches hole, the tool jointshould have the smallest OD possible to provide sufficient fishability.

Further, the standard API 5½-inches drill pipe represents an over-designfor holes smaller than 8½-inches with a limited-to-no fishability by wayof overshot due to a 7¼-inches OD NC50 tool joint, especially indeviated holes.

Improved Hole Cleaning

The present invention (e.g., 5¼-inches drill pipe with EVRDRL49Gdouble-shoulder connections) has an improved hole cleaning over thestandard API 5-inches drill pipe due to the tool joint OD in relation tohole size.

For a standard API 5-inches drill pipe, hole cleaning is limited by amaximum flow rate of drilling fluid generated by a drilling rig pump.Many drilling rigs lack sufficient pump horsepower to generate the flowrate to achieve sufficient annular velocity to clean the hole.

Further, the standard API 5½-inches drill pipe represents an over-designfor holes smaller than 8½-inches, with large, bulky tool jointsrestricting the ability of the drilling fluid to remove cuttings fromthe annulus.

Summary

The present invention (e.g., 5¼-inches drill pipe) provides hydraulicperformance comparable to the standard API 5½-inches drill pipe in a12¼-inches hole and superior to the standard API 5-inches and 5½-inchesdrill pipe in 7⅞-inches or 8½-inches holes. The present invention (e.g.,5¼-inches drill pipe with EVRDRL49G double shoulder connections)maximizes the tool joint ID for improved hydraulics (and a lessobstructed path for tools) and minimizes tool joint OD for improvedfishability and hole cleaning in high angle holes.

Further, the present invention (e.g., 5¼-inches drill pipe) extends thedrilling envelope by allowing engineers to select a single size drillpipe (e.g., 5¼-inches drill pipe) for multiple hole geometries.

Drillstring/Drill Pipe Design Analysis

Prior to field applications, load and stability analyses were performedon the drill string, considering the standard API 5-inches drill pipe orthe present invention (e.g., 5¼-inches drill pipe). The well planincluded a 3-casing string design with long, 8½-inches or 7⅞-incheshorizontal holes across the pay zones at TD. See FIG. 29.

An objective of the analysis was to confirm that the present invention(e.g., 5¼-inches drill pipe) could replace the standard API 5-inchesdrill pipe in a pad drilling application where both 8½-inches and7⅞-inches production intervals are drilled from a single surfacelocation.

The design of the drill string and/or drill pipe was based on the drillpipe's structural requirements, geometric requirements and componentcosts. The drill string and/or drill pipe was analyzed under thefollowing conditions and operational modes:

1. at hole inclination of 30-degree, 60-degree and 90-degree2. in hole sizes of 12¼-inches, 7⅞-inches and 8½-inches3. at a measured depth of 11,246 feet MD/TVD and 21,900 feet MD (11,958feet TVD).4. for S-135 grade, Range-2 drill pipe and nominal wall: 5-inches (i.e.,0.362-inch wall) vs. 5¼-inches (i.e., 0.375-inch wall)5. at design flow rate limits of 900 gpm for a 12¼-inches hole and 600gpm for a 7⅞-inches and 8½-inches holes.

The well path for the study was based on a vertical hole to KOP at11,282 feet TVD, a build rate of 12 degrees/100 feet to a maximuminclination of 90-degrees and a hole size at total measured depth of7⅞-inches, and with an 8⅝-inches casing set at 11,246 feet. The mud typein the lateral was 12.8 pound per gallon (lb/gal.) oil-based mud (OBM),with cut brine for surface and intermediate holes. The assumed frictionfactors were 0.25 for the casing and 0.30 for the open hole.

The drill string and/or drill pipe stability was addressed from twoperspectives:

1. the stability effect on drill pipe fatigue in rotary mode drilling;and2. the stability effect on static stress levels in sliding modedrilling.

Structural Requirements

The drill string and/or drill pipe structural requirements are primarilydefined by torsional, tensile and buckling loads on the drill pipeduring operations. The drill pipe and tool joints must have thetorsional strength needed to rotate the drill string when drilling andwhen coming out of the hole. The drill pipe must have the tensilestrength to pull the drill string out of the hole. Further, the drillpipe must have the buckling strength to transfer weight from the buildzone to the drill bit. Except for tension and buckling, these loads areoften applied simultaneously.

In addition, the drill string and/or drill pipe structural requirementare also defined by other factors (e.g., external and internal pressurecapabilities) of the drill pipe during operations.

Geometric Requirements

The drill string and/or drill pipe must be designed for a specific holeor casing. For example, the drill pipe should be large enough tooptimize the drilling hydraulics program yet have small enough tooljoints to be fished. Bit hydraulic horsepower and annular velocity aredrilling parameters that depend on the flow rate of the drilling fluid.Larger ID drill pipe can minimize pressure losses and decrease pumphorsepower. The drill pipe acts as a conduit for pumping drilling fluidto the bit and to bring the fluid and cutting back to the surface.Pressure losses caused by pumping the fluid to and from the drill bitmust be minimized and the velocity of the fluid in the annulus (betweenthe pipe and wall of the hole) must be sufficient to bring the cuttingsback to the surface. A large tool joint bore diameter will have apositive effect on drilling hydraulics. The pipe must be fishable inside8⅝-inches casing or 7⅞-inches open hole sections. The tool joints areselected so that there is adequate annular clearance for fishing tools.The drill pipe must be handled with conventional elevators to avoidspecial handling equipment and additional handling costs. The differencebetween the diameter of the tool joints and the diameter of the drillpipe body must be large enough to provide enough contact area to allowuse of standard 18-degree tapered elevators.

Component Costs

A cost savings may be realized with the present invention (e.g.,5¼-inches drill pipe) compared to the standard API 5½-inches drill pipeby permitting smaller production hole sizes and use of a single stringfor both intermediate and production holes (i.e., 7⅞-inches and larger).The drill string and/or drill pipe costs include costs associated withperformance enhancing features (e.g., pin tool joint-to-tube tapers,proprietary connections, tool joint hardfacings and internal/externalcoatings) to extend the service life of components, and costs relatingto utilization of drill pipe in the field. Further, costs associatedwith using the drill pipe include handling (on the rig and during pipemovement) and interfacing with other drill string components.

Drill Pipe Optimization Model

As discussed above, the 5¼-inches drill pipe may be designed for a givenproduction hole size (e.g., 7⅞-inches, 8½-inches and 12¼-inches) andcompared to commonly selected 5-inch and 5½-inches drill pipe. Suchdesign can be a tedious process.

To further improve the 5¼-inches drill pipe design, an optimizationmodel was developed. This optimization model predicts an anticipatedperformance of the drill string with respect to strength and pressureloss.

In general, a strength of drill pipe will be maximized when the OD ofthe drill pipe is as large as possible within a given production holesize and the ID of the drill pipe is as small as possible. These twofactors tend to increase strength of the drill pipe, weather that betensile, torsional, or buckling capacity.

Further, a pressure loss during drilling with a particular drill stringin a particular well will be minimized when the OD of the drill pipe isas small as possible, the ID of the drill pipe is as large as possible,and the drill pipe cross-section is optimally placed within theproduction hole.

Given the above general concepts, an optimization model was developed topredict an anticipated performance of a proposed drill string in aparticular production hole size. A general relationship for theoptimization model is:

${Ro} = \frac{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}\mspace{14mu} {strength}}{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}\mspace{14mu} {pressure}\mspace{14mu} {loss}}$

where Ro is an “Optimization Ratio.”

In the optimization model, the “Geometric Factors which affect strength”of the drill string may be any suitable geometric factors relating tostrength of the drill string. For example, suitable “Geometric Factorswhich affect strength” of the drill string include, but are not limitedto, drill pipe OD and drill pipe ID. The drill pipe OD may berepresented as Pod; and the drill pipe ID may be represented as Pid.

A general relationship for the numerator of the optimization model is:

Geometric Factors which affect strength=Geometric Factors which increasestrength−Geometric Factors which decrease strength

For example, if the “Geometric Factors which affect strength” areapproximated by Pod and Pid, the numerator of the optimization model is:

Geometric Factors which affect strength=Pod−Pid

In the optimization model, the “Geometric Factors which affect pressureloss” of the drill string may be any suitable geometric factors relatingto the pressure loss of the drill string. For example, suitable“Geometric Factors which affect pressure loss” of the drill stringinclude but are not limited to, two primary OD's (e.g., drill pipe ODand tool joint OD) and two primary ID's (e.g., drill pipe ID and tooljoint ID), and production hole size.

To simplify the expression, a concept of “equivalent ID” and “equivalentOD” may be used to simplify the relationship for the denominator. Theequivalent OD and ID are the theoretical continuous OD and ID,respectively, that would result in the same pressure loss in a givencasing as the actual drill pipe. These theoretical calculations resultin an Equivalent OD (EQod) and Equivalent ID (EQid) which account forthe complexity of the drill pipe geometry and the production hole size.

For example, if Geometric Factors which affect pressure loss areapproximated by EQod and EQid, the demoninator of the optimization modelis:

Geometric Factors which affect pressure loss=EQod−EQid

Substituting these two approximations into the general relationshipresults in a simplified relationship for the optimization model:

${Ro} = \frac{{Pod} - {Pid}}{{EQod} - {EQid}}$

As described above, the “Optimization Ratio” will tend to be maximizedas the drill pipe strength is maximized and the drill pipe pressure lossis minimized.

As shown, a 5¼-inches drill pipe is designed for a given production holesize (e.g., 7⅞-inches, 8½-inches and 12¼-inches) and compared tocommonly selected 5-inch and 5½-inch drill pipe. The EQod and EQid werecalculated using a “power law.” Table 8 shows the calculations of EQodand EQid using the “power law”.

TABLE 8 Calculated EQod and EQid Values Drill Tool Hole Flow Pipe DrillJoint Tool Power Law Size Rate OD Pipe ID OD Joint ID EQod EQid 12lb/gal mud (in.) (gpm) (in.) (in.) (in.) (in.) (in.) (in.) 5-inch, 19.5#(0.362- 7.875 600 5.000 4.276 6.625 3.250 5.480 4.117 inch wall) DrillPipe 8.500 600 5.350 4.117 with 6.625-inch × 12.250 900 5.190 4.1163.25-inch Tool Joints 5¼-inch, 20.7# 7.875 600 5.250 4.528 6.250 3.5005.422 4.375 (0.361-inch wall) Drill 8.500 600 5.392 4.375 Pipe with6.250-inch × 12.250 900 5.349 4.375 3.500-inch Tool Joints 5½-inch,21.9# 7.875 600 5.500 4.778 7.250 3.500 6.423 4.560 (0.361-inch wall)Drill 8.500 600 6.049 4.560 Pipe with 7.250-inch × 12.250 900 5.7214.560 3.500-inch Tool Joints

Given these calculations of EQod and EQid, the “Optimization Ratio” maybe approximated for drill pipe (e.g., 5-inches, 5¼-inches and 5½-inches)in a given production hole (e.g., 7⅞-inches, 8½-inches and 12¼-inches).Table 9 shows the approximation of Ro using the simplified optimizationmodel.

TABLE 9 Ro Approximation Power Law 12 lb/gal mud Hole Size (in.) FlowRate (gpm) Ro 5-inch 19.5# (0.362- 7.875 600 0.531 inch wall) Drill Pipe8.500 600 0.587 with 6.625-inch × 12.250 900 0.674 3.25-inch Tool Joints5¼-inch 20.7# 7.875 600 0.690 (0.361-inch wall) 8.500 600 0.710 DrillPipe with 6.250- 12.250 900 0.741 inch × 3.500-inch Tool Joints 5½-inch21.9# 7.875 600 0.388 (0.361-inch wall) 8.500 600 0.485 Drill Pipe with7.250- 12.250 900 0.622 inch × 3.500-inch Tool Joints

As shown by Tables 8 and 9, Ro may be maximized for a 5¼-inches drillpipe in these given production holes (i.e., 7⅞-inches, 8½-inches and12¼-inches).

In an embodiment, the “Optimization Ratio” may be at least about 0.68for a given production hole (e.g., 7⅞-inches, 8½-inches and 12¼-inches),and any range or value there between. In an embodiment, the“Optimization Ratio” may be at least about 0.68 for a production hole ofabout 7⅞-inches, and any range or value there between. In an embodiment,the “Optimization Ratio” may be at least about 0.70 for a productionhole of about 8½-inches, and any range or value there between. In anembodiment, the “Optimization Ratio” may be at least about 0.72 for aproduction hole of about 12¼-inches, and any range or value therebetween.

In an embodiment, the “Optimization Ratio” may be at least about 0.68for a given production hole (e.g., 7⅞-inches, 8½-inches and 12¼-inches)and at a flow rate from about 600 to about 900 gallons per minute (gpm),and any range or value there between. In an embodiment, the“Optimization Ratio” may be at least about 0.68 for a production hole ofabout 7⅞-inches and at a flow rate of about 600 gpm, and any range orvalue there between. In an embodiment, the “Optimization Ratio” may beat least about 0.70 for a production hole of about 8½-inches and at aflow rate of about 600 gpm, and any range or value there between. In anembodiment, the “Optimization Ratio” may be at least about 0.72 for aproduction hole of about 12¼-inches and at a flow rate of about 900 gpm,and any range or value there between.

In an embodiment, the “Optimization Ratio” may be at least about 0.68for a given production hole (e.g., 7⅞-inches, 8½-inches and 12¼-inches)and at a flow rate from about 600 to about 900 gpm of 12 lb/gal. mud,and any range or value there between. In an embodiment, the“Optimization Ratio” may be at least about 0.68 for a production hole ofabout 7⅞-inches and at a flow rate of about 600 gpm of 12 lb/gal. mud,and any range or value there between. In an embodiment, the“Optimization Ratio” may be at least about 0.70 for a production hole ofabout 8½-inches and at a flow rate of about 600 gpm of 12 lb/gal. mud,and any range or value there between. In an embodiment, the“Optimization Ratio” may be at least about 0.72 for a production hole ofabout 12¼-inches and at a flow rate of about 900 gpm of 12 lb/gal. mud,and any range or value there between.

Obviously, this “Optimization Ratio” should not be considered as a solefactor in selecting a drill pipe for a given production hole.

Also, when comparing the “Optimization Ratios” of a designed drill pipeand other drill pipe, the drill pipe selected for comparison shouldideally have at least acceptable strength and pressure losscharacteristics. In other words, the drill pipe selected for comparisonshould already be considered “strong enough” and/or have nominallyacceptable flow characteristics for the application.

Improved Drill Pipe

FIG. 34 illustrates cross-sectional view of an improved drill pipe 3400according to an embodiment of the present invention, showing a tooljoint box 3468 at one end and a tool joint pin 3474 at the other. Asshown in FIG. 34, the drill pipe 3400 comprises a tool joint box 3468having a tool joint box outer diameter 3470 and a tool joint box innerdiameter 3472, and a tool joint pin 3474 having a tool joint pin outerdiameter 3476 and a tool joint pin inner diameter 3478.

In an embodiment, the tool joint box outer diameter 3470 may be fromabout 6.1-inches to about 6.4-inches, and any range or value therebetween. In an embodiment, the tool joint box diameter 3470 may be about6.25-inches. In an embodiment, the tool joint box diameter 3470 may beabout 6.25-inches for a 5¼-inches drill pipe. In an embodiment, the tooljoint box diameter 3470 may be about 6.25-inches for a 5¼-inches 20.70ppf (i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint box inner diameter 3472 may be fromabout 3.4-inches to about 3.6-inches, and any range or value therebetween. In an embodiment, the tool joint box inner diameter 3472 may beabout 3.5-inches. In an embodiment, the tool joint box inner diameter3472 may be about 3.5-inches for a 5¼-inches drill pipe. In anembodiment, the tool joint box inner diameter 3472 may be about3.5-inches for a 5¼-inches 20.70 ppf (i.e., 0.361-inch wall thickness),S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint pin outer diameter 3476 may be fromabout 6.1-inches to about 6.4-inches, and any range or value therebetween. In an embodiment, the tool joint pin diameter 3476 may be about6.25-inches. In an embodiment, the tool joint pin diameter 3476 may beabout 6.25-inches for a 5¼-inches drill pipe. In an embodiment, the tooljoint pin diameter 3476 may be about 6.25-inches for a 5¼-inches 20.70ppf (i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint pin inner diameter 3478 may be fromabout 3.4-inches to about 3.6-inches, and any range or value therebetween. In an embodiment, the tool joint pin inner diameter 3478 may beabout 3.5-inches. In an embodiment, the tool joint pin inner diameter3478 may be about 3.5-inches for a 5¼-inches drill pipe. In anembodiment, the tool joint pin inner diameter 3478 may be about3.5-inches for a 5¼-inches 20.70 ppf (i.e., 0.361-inch wall thickness),S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint box 3468 may comprise an optional boxhardband 3480 having a box hardband outer diameter 3478 for extradownhole wear protection. In an embodiment, the box hardband 3480 maycomprise an extra component (e.g., welded wire) attached to the tooljoint box 3468.

In an embodiment, the box hardband diameter 3478 may be from about6.3-inches to about 6.6-inches, and any range or value there between. Inan embodiment, the box hardband diameter 3478 may be about 6.438-inches.In an embodiment, the box hardband diameter 3478 may be about6.438-inches for 5¼-inches drill pipe. In an embodiment, the boxhardband diameter 3478 may be about 6.438-inches for 5¼-inches 20.70 ppf(i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

n an embodiment, the tool joint pin 3474 may comprise an optional pinhardband 3484 having a pin hardband outer diameter 3486 for extradownhole wear protection. In an embodiment, the pin hardband 3484 maycomprise an extra component (e.g., welded wire) attached to the tooljoint pin 3474.

In an embodiment, the pin hardband diameter 3484 may be from about6.3-inches to about 6.6-inches, and any range or value there between. Inan embodiment, the pin hardband diameter 3484 may be about 6.438-inches.In an embodiment, the pin hardband diameter 3484 may be about6.438-inches for 5¼-inches drill pipe. In an embodiment, the pinhardband diameter 3484 may be about 6.438-inches for 5¼-inches, 20.70ppf (i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint box 3468 comprises a tapered elevatorshoulder 3488 having a tapered elevator shoulder angle 3490.

In an embodiment, the tapered elevator shoulder angle 3490 may be from16 degrees to about 20 degrees, and any range or value between. In anembodiment, the tapered elevator shoulder angle 3490 may be about 18degrees. In an embodiment, the tapered elevator shoulder angle 3490 maybe about 18 degrees for 5¼-inches drill pipe. In an embodiment, thetapered elevator shoulder angle 3490 may be about 18 degrees for5¼-inches, 20.70 ppf (i.e., 0.361-inch wall thickness), S-135 grade,Range-2 drill pipe.

In an embodiment, the tool joint pin 3474 comprises a tapered pinshoulder 3492 having a pin shoulder angle 3494.

In an embodiment, the taper pin shoulder angle 3494 may be from about 16degrees to about 36 degrees, and any range or value there between. In anembodiment, the tapered pin shoulder angle 3494 may be about 18 degrees.In an embodiment, the tapered pin shoulder angle 3494 may be about 18degrees for 5¼-inches drill pipe. In an embodiment, the tapered pinshoulder angle 3494 may be about 18 degrees for 5¼-inches, 20.70 ppf(i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the drill pipe 3400 comprises a tool joint box 3468, atool joint pin 3474 and a drill pipe body 34104.

In an embodiment, the tool joint box 3468 may have a drill pipe box weldneck 3496 in a region of a drill pipe box body upset 3498 having a drillpipe box body upset inner diameter 3499.

In an embodiment, the drill pipe box body upset inner diameter 3499 maybe from about 3.66-inches to about 3.85-inches, and any range or valuethere between. In an embodiment, the drill pipe box body upset innerdiameter 3499 may be about 3.752-inches. In an embodiment, the drillpipe box body upset inner diameter 3499 may be about 3.752-inches for5¼-inches drill pipe. In an embodiment, the drill pipe box body upsetinner diameter 3499 may be about 3.752-inches for 5¼-inches, 20.70 ppf(i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint pin 3474 may have a drill pipe pin weldneck 34100 in a region of a drill pipe pin body upset 34102 having adrill pipe pin body upset inner diameter 34103.

In an embodiment, the drill pipe pin body upset inner diameter 34103 maybe from about 3.66-inches to about 3.85-inches, and any range or valuethere between. In an embodiment, the drill pipe pin body upset innerdiameter 34103 may be about 3.752-inches. In an embodiment, the drillpipe pin body upset inner diameter 34103 may be about 3.752-inches for5¼-inches drill pipe. In an embodiment, the drill pipe pin body upsetinner diameter 34103 may be about 3.752-inches for 5¼-inches, 20.70 ppf(i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the drill pipe body 34104 has a drill pipe body outerdiameter 34106 and a drill pipe body inner diameter 34108.

In an embodiment, the drill pipe body outer diameter 34106 may be fromabout 5.1-inches to about 5.4-inches, and any range or value therebetween. In an embodiment, the drill pipe body outer diameter 34106 maybe about 5.25-inches for 5¼-inches drill pipe. In an embodiment, thedrill pipe body outer diameter 34106 may be about 5.25-inches for5¼-inches, 20.70 ppf (i.e., 0.361-inch wall thickness), S-135 grade,Range-2 drill pipe.

In an embodiment, the drill pipe body inner diameter 34108 may be fromabout 4.4-inches to about 4.6-inches, and any range or value therebetween. In an embodiment, the drill pipe body inner diameter 34108 maybe about 4.528-inches for 5¼-inches drill pipe. In an embodiment, thedrill pipe body inner diameter 34108 may be about 4.528-inches for5¼-inches, 20.70 ppf (i.e., 0.361-inch wall thickness), S-135 grade,Range-2 drill pipe.

In an embodiment, the drill pipe body 34104 has a drill pipe wallthickness 34110.

In an embodiment, the drill pipe wall thickness 34110 may be from about0.352-inch to about 0.370-inch, and any range or value there between. Inan embodiment, the drill pipe wall thickness 34110 may be about0.361-inch. In an embodiment, the drill pipe wall thickness 34110 may beabout 0.361-inch for 5¼-inches drill pipe. In an embodiment, the drillpipe wall thickness 34110 may be about 0.361-inch for 5¼-inches, 20.70ppf (i.e., 0.361-inch wall thickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the drill pipe 3400 having a drill pipe length 34112comprises a tool joint box 3468 having a tool joint box length 34114, atool joint pin 3474 having a tool joint pin length 34116 and a drillpipe body 34104 having a drill pipe body length (i.e., drill pipelength−(tool joint box length+tool joint pin length)).

In an embodiment, the drill pipe length 34112 may be from about 25-feetto about 50-feet, and any range or value there between. In anembodiment, the drill pipe length 34112 may be about 31.5-feet. In anembodiment, the drill pipe length 34112 may be about 31.5-feet for5¼-inches drill pipe. In an embodiment, the drill pipe length 34112 maybe about 31.5-feet for 5¼-inches, 20.70 ppf (i.e., 0.361-inch wallthickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the drill pipe length 34112 may be about 45-feet toabout 47-feet. In an embodiment, the drill pipe length 34112 may beabout 45-feet to about 47-feet for 5¼-inch drill pipe. In an embodiment,the drill pipe length 34112 may be about 45-feet to about 47-feet for5¼-inch, Range-3 drill pipe. Longer drill pipe lengths reduce the numberof tool joint connections, resulting in fewer potential damage points tomaintain and repair.

In an embodiment, the tool joint box length 34114 may be from about15-inches to about 19-inches, and any range or value there between. Inan embodiment, the tool joint box 34114 may be about 17-inches. In anembodiment, the tool joint box 34114 may be about 17-inches for5¼-inches drill pipe. In an embodiment, the tool joint box 34114 may beabout 17-inches for 5¼-inches, 20.70 ppf (i.e., 0.361-inch wallthickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint pin length 34116 may be from about12.5-inches to about 15.5-inches, and any range or value there between.In an embodiment, the tool joint pin 34116 may be about 14-inches. In anembodiment, the tool joint pin 34116 may be about 14-inches for5¼-inches drill pipe. In an embodiment, the tool joint pin 34116 may beabout 14-inches for 5¼-inches, 20.70 ppf (i.e., 0.361-inch wallthickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the drill pipe 3400 having a drill pipe length 34112comprises a tool joint box 3468 having a tool joint box length 34114, atool joint pin 3474 having a tool joint pin length 34116, a drill pipebody 34104 having a drill pipe body length (i.e., drill pipelength−(tool joint box length+tool joint pin length)), and a rotaryshoulder connection 34118 having a rotary connection length 34120.

In an embodiment, the rotary shoulder connection length 34120 may befrom about 4.275-inches to about 5.225-inches, and any range or valuethere between. In an embodiment, the rotary shoulder connection length34120 may be about 4.75-inches. In an embodiment, the rotary shoulderconnection length 34120 may be about 4.75-inches for 5¼-inches drillpipe. In an embodiment, the rotary shoulder connection length 34120 maybe about 4.75-inches for 5¼-inches, 20.70 ppf (i.e., 0.361-inch wallthickness), S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint box 3468 may have a drill pipe boxfriction weld 34122 (i.e., a theoretical “physical” location of theweld) having a box friction weld outer diameter 34124 in a region of adrill pipe box body upset 3498.

In an embodiment, the box friction weld outer diameter 34124 may be fromabout 5.22-inches to about 5.48-inches, and any range or value therebetween. In an embodiment, the box friction weld outer diameter 34124may be about 5.350-inches. In an embodiment, the box friction weld outerdiameter 34124 may be about 5.350-inches for 5¼-inches drill pipe. In anembodiment, the box friction weld outer diameter 34124 may be about5.350-inches for 5¼-inches, 20.70 ppf (i.e., 0.361-inch wall thickness),S-135 grade, Range-2 drill pipe.

In an embodiment, the tool joint pin 3474 may have a drill pipe pinfriction weld 34126 (i.e., a theoretical “physical” location of theweld) having a pin friction weld outer diameter 34128 in a region of adrill pipe pin body upset 34102.

In an embodiment, the pin friction weld outer diameter 34128 may be fromabout 5.22-inches to about 5.48-inches, and any range or value therebetween. In an embodiment, the pin friction weld outer diameter 34128may be about 5.350-inches. In an embodiment, the pin friction weld outerdiameter 34128 may be about 5.350-inches for 5¼-inches drill pipe. In anembodiment, the pin friction weld outer diameter 34128 may be about5.350-inches for 5¼-inches, 20.70 ppf (i.e., 0.361-inch wall thickness),S-135 grade, Range-2 drill pipe.

In an embodiment, In an embodiment, the drill pipe 3400 having a drillpipe length 34112 comprises a tool joint box 3468 having a tool jointbox length 34114, a tool joint pin 3474 having a tool joint pin length34116, a drill pipe body 34104 having a drill pipe body length (i.e.,drill pipe length−(tool joint box length+tool joint pin length)) and adouble shoulder connection having a double shoulder connection length,as discussed below.

In an embodiment, the double shoulder connection length may be fromabout 4.275-inches to about 5.225-inches, and any range or value therebetween. In an embodiment, the double shoulder connection length may beabout 4.75-inches. In an embodiment, the double shoulder connectionlength may be about 4.75-inches for 5¼-inches drill pipe. In anembodiment, the double shoulder connection length may be about4.75-inches for 5¼-inches, 20.70 ppf (i.e., 0.361-inch wall thickness),S-135 grade, Range-2 drill pipe.

In an embodiment, the improved drill pipe 3400 may be made of anysuitable material. For example, suitable materials include, but are notlimited to, low alloy steels (e.g., 4140, 4145, 4330, etc.), stainlesssteels (e.g., 17-4, 304, 316, etc.), super alloys (e.g., Inconel),titanium alloys (e.g., Ti-6Al-4V, Ti-6Al-6V-2Sn, etc.), copper alloys(e.g., Beryllium copper), cobalt alloys (e.g., Stellite), aluminumalloys (e.g., 2024, 6061,7075, etc.), and combinations and variationsthereof. In an embodiment, the improved drill pipe 3400 may be low alloysteels or stainless steels.

As shown in FIGS. 1A-1B, 4A-4B and 34, the double-shoulder connection100 comprises a box connection 110, 410, 3410 having a box axis(centerline) 112, 412, 3412, a pin connection 130, 430, 3430 having apin axis (centerline) 132, 432, 3432, a primary shoulder 150, 450 and asecondary shoulder 160, 460.

In an embodiment, the box connection 110, 3410 comprises a box axis(centerline) 112, 3412, a box outer radius 114, 3414, a box bevel radius116, a box counter bore radius 118, 3418, a box inner radius 120, 3420,a box depth 122, 3422, a box taper 124 and box threads 126 cut along thebox taper 124. The box connection 110, 3410 is a female, internallythreaded half of the double-shoulder connection 100, similar to a nut.See FIGS. 1A & 1B.

In an embodiment, the pin connection 130, 3430 comprises a pin axis(centerline) 132, 3432, a pin outer radius 134, 3434, a pin bevel radius136, a pin cylinder radius 138, 3438, a pin nose radius 140, 3440, a pinlength 142, 3442, a pin taper 144 and pin threads 146 cut along the pintaper 144. The pin connection 130, 3430 is a male, externally threadedhalf of the double-shoulder connection 100, similar to a bolt. See FIGS.1A & 1B.

In an embodiment, any suitable connection box/pin taper 124, 144 may beused for the box/pin connection 100. For example, suitable connectionbox/pin taper 124, 144 may be from about ¾ inch per foot to about 3inches per foot, and any range or value there between.

In an embodiment, any suitable thread pitch may be used for the boxthreads 126, 426, 526, 626, 726, 826, 926, 1026, 1226, 1426, 1726, 1826,19, 26, 2026, 2126, 2226, 2326, 2426, 2626 and/or pin threads 146, 446,546, 646, 746, 846, 946, 1046, 1246, 1446, 1746, 1846, 1946, 2046, 2146,2246, 2346, 2446, 2646. For example, suitable thread pitches may be fromabout 3 threads per inch to about 5 threads per inch, and any range orvalue there between.

In an embodiment, any suitable thread form 1100 may be used for the boxthreads 126, 426, 526, 626, 726, 826, 926, 1026, 1226, 1426, 1726, 1826,1926, 2026, 2126, 2226, 2326, 2426, 2626 and/or pin threads 146, 446,546, 646, 746, 846, 946, 1046, 1246, 1446, 1746, 1846, 1946, 2046, 2146,2246, 2346, 2446, 2646. See FIG. 11. Suitable thread forms 1100 may havevarious crest 1110, 1112, flank 1130, 1140 and root 1160 shapes with anincluded angle 1150 from about 29 degrees to about 90 degrees, and anyrange or value there between, as discussed below.

In an embodiment, the primary shoulder 150, 450 may be an angled primaryshoulder, as discussed below. As shown in FIGS. 4A-4B, the primaryshoulder 450 comprises a primary box shoulder 452 at a primary box angle454 with respect to a first perpendicular 480 to the box axis 412 at afirst end point 482 of the box connection; and a primary pin shoulder456 at a primary pin angle 458 with respect to a first perpendicular 480to the pin axis 432 at the first end point 482 of the pin connection.See also FIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made up).

In an embodiment, the secondary shoulder 160, 660 may be an angledsecondary shoulder, as discussed below. As shown in FIGS. 6A-6B, thesecondary shoulder 160, 660 comprises a secondary box shoulder 662 at asecondary box angle 664 with respect to a second perpendicular 686 tothe box axis 612 at a second end point 688 of the box connection; and asecondary pin shoulder 666 at a secondary pin angle 668 with respect toa second perpendicular 686 to the pin axis 632 at the second end point688 of the pin connection. See also FIG. 1A: 112 & FIG. 1B: 132 (showingbox and pin made up).

In an embodiment, the primary shoulder 150, 1750 may be a curved primaryshoulder. As shown in FIGS. 17A-17B, the primary shoulder 1750 comprisesa primary box shoulder 1752 defined by a primary axial box radius height1790, a primary box center point 1792 and a primary box radius 1794, anda primary pin shoulder defined by a primary axial pin radius height1796, a primary pin center point 1798 and a primary pin radius 17100.See also FIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made up).

In an embodiment, the secondary shoulder 160, 1960 may be a curvedsecondary shoulder. As shown in FIGS. 19A-19B, the secondary shoulder1960 comprises a secondary box shoulder 1962 defined by a secondary boxaxial box radius height 19102, a secondary box center point 19104 and asecondary box radius 19106, and a secondary pin shoulder 1966 defined bya secondary axial pin radius height 19106, a secondary pin center point19110 and a secondary pin radius 19112. See also FIG. 1A: 112 & FIG. 1B:132 (showing box and pin made up).

Double-Shoulder Connection with Box and Pin Made-Up

FIG. 1A illustrates a partial cross-sectional view of a double-shoulderconnection 100 with a pin and box made-up (screwed together), showingbox connection 110 features; and FIG. 1B illustrates the double-shoulderconnection 100 of FIG. 1A, showing pin connection 130 features. As shownin FIGS. 1A & 1B, the double-shoulder connection 100 comprises a boxconnection 110 having a box axis (centerline) 112, a pin connection 130having a pin axis (centerline) 132, a primary shoulder 150 and asecondary shoulder 160.

In an embodiment, the box connection 110 comprises a box axis(centerline) 112, a box outer radius 114, a box bevel radius 116, a boxcounter bore radius 118, a box inner radius 120, a box depth 122, a boxtaper 124 and box threads 126 cut along the box taper 124. The boxconnection 110 is a female, internally threaded half of thedouble-shoulder connection 100, similar to a nut. See FIGS. 1A & 1B.

In an embodiment, the pin connection 130 comprises a pin axis(centerline) 132, a pin outer radius 134, a pin bevel radius 136, a pincylinder radius 138, a pin nose radius 140, a pin length 142, a pintaper 144 and pin threads 146 cut along the pin taper 144. The pinconnection 130 is a male, externally threaded half of thedouble-shoulder connection 100, similar to a bolt. See FIGS. 1A & 1B.

In an embodiment, any suitable connection box/pin taper 124, 144 may beused for the box/pin connection 100. For example, suitable connectionbox/pin taper 124, 144 may be from about ¾ inch per foot to about 3inches per foot, and any range or value there between.

In an embodiment, any suitable thread pitch may be used for the boxthreads 426, 526, 626, 726, 826, 926, 1026, 1226, 1426, 1726, 1826, 19,26, 2026, 2126, 2226, 2326, 2426, 2626 and/or pin threads 446, 546, 646,746, 846, 946, 1046, 1246, 1446, 1746, 1846, 1946, 2046, 2146, 2246,2346, 2446, 2646. For example, suitable thread pitches may be from about3 threads per inch to about 5 threads per inch, and any range or valuethere between.

In an embodiment, any suitable thread form 1100 may be used for the boxthreads 426, 526, 626, 726, 826, 926, 1026, 1226, 1426, 1726, 1826,1926, 2026, 2126, 2226, 2326, 2426, 2626 and/or pin threads 446, 546,646, 746, 846, 946, 1046, 1246, 1446, 1746, 1846, 1946, 2046, 2146,2246, 2346, 2446, 2646. Suitable thread forms 1100 may have variouscrest 1110, 1112, flank 1130, 1140 and root 1160 shapes with an includedangle 1150 from about 29 degrees to about 90 degrees, and any range orvalue there between, as discussed below. Standard (Typical) DoubleShoulder Connections

FIG. 2A illustrates a cross-sectional view of a standard (typical)double-shoulder 200 connection, showing a standard primary shoulderconnection 250 and a standard secondary shoulder connection 260. Asshown in FIG. 2A, the standard (typical) double-shoulder connection 200comprises a box connection 210 having a box axis 112, a pin connection230 having a pin axis 132, a primary shoulder 250 and a secondaryshoulder 260.

The primary shoulder 250 comprises a primary box shoulder 252 at aprimary box angle with respect to a first perpendicular 280 to the boxaxis 112 at a first end point 282 of the box connection; and a primarypin shoulder 256 at a primary pin angle with respect to the firstperpendicular 280 to the pin axis 132 at the first end point 282 of thepin connection. See also FIG. 1A: 112 & FIG. 1B: 132 (showing box andpin made-up).

In a standard double-shoulder connection, the primary box angle is 0degrees (i.e., primary box shoulder 252 is perpendicular to the box axis112) and the primary pin angle is 0 degrees (i.e., primary pin shoulder256 is perpendicular to the pin axis 132).

The secondary shoulder 260 comprises a secondary box shoulder 262 at asecondary box angle with respect to the box axis 112; and a secondarypin shoulder 266 at a secondary pin angle with respect to the pin axis132. See also FIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made-up).

In a standard double-shoulder connection, the secondary box angle is 0degrees (i.e., secondary box shoulder 262 is perpendicular to the boxaxis 112) and the secondary pin angle is 0 degrees (i.e., secondary pinshoulder 266 is perpendicular to the pin axis 132).

FIG. 2B illustrates a detailed view C1 in FIG. 2A, showing the standardprimary shoulder connection. As shown in FIG. 2B, the primary box angleis 0 degrees and the primary pin angle is 0 degrees.

FIG. 2C illustrates a detailed view C2 in FIG. 2A, showing the standardsecondary shoulder connection. As shown in FIG. 2C, the secondary boxangle is 0 degrees and the secondary pin angle is 0 degrees.

As discussed in the “Background of the Invention” section, standard(typical) double-shoulder connections 300 and standard (typical)single-shoulder connections suffer from the problem of box “swell”(e.g., box material yields) due to tapered threads, included threadprofile angle (see FIG. 11: 1150) and high generated axial compressiveloads. FIG. 3A illustrates a cross-sectional view of the standard(typical) double-shoulder connection 200, 300 shown in FIG. 2A, showingan exaggerated deformation of the box connection 210, 310 and the pinconnection 230, 330 for clarity purposes.

Standard (typical) double shoulder connection 200, 300 and standard(typical single shoulder connections suffer from the problem of boxswell (e.g., box material yields). As shown in FIG. 3A, the boxswell/yielding forces force the primary shoulder 350 of the boxconnection 310 outward such that the box connection 210, 310 swells(e.g., box material yields), causing deformation of and/or permanentdamage to the box connection 210, 310.

Standard (typical) double-shoulder connections 200, 300 and standard(typical) single-shoulder connections also suffer from the problem ofpin collapse. As shown in FIG. 3A, the pin collapse forces push aportion of the pin nose inward, causing deformation of and/or permanentdamage to the pin connection 230, 330.

Further, the cyclic box swell/yielding forces are transmitted into, forexample, a first pin thread and a second pin thread resulting in damageto the first pin thread and the second pin thread (i.e., initiallycausing cracks at the root of the pin threads and, ultimately, failureof the pin threads). This combination of box swell (e.g., box materialyields) and pin collapse can lead to misalignment of the box threads226, 326 and the pin threads 246, 346, as well as permanent damage tothe box connection 210, 310 and/or the pin connection 230, 330. FIG. 3Billustrates a detailed view D in FIG. 3A, showing a thread misalignment.As shown in FIG. 3B, the box threads 226, 326 are misaligned with thepin threads 246, 346, causing damage to the box threads 226, 326 and/orthe pin threads 246, 346.

In addition, this combination of box swell and pin collapse, inconjunction with high alternating axial, torsional, and bending loads,can lead to premature fatigue failure (e.g., material yields) of thestandard (typical) double-shoulder connection 200, 300 and the standard(typical) single-shoulder connection, damage to the box threads 226, 326and/or the pin threads 246, 346, and permanent deformation of the boxconnection 210, 310 and/or the pin connection 230, 330.

Improved Double-Shoulder Connections with Angled Primary Shoulder and/orSecondary Shoulder

An angled primary shoulder 450 reduces box swell (e.g., box materialsyields) and provides better alignment of the box threads 426 and pinthreads 446 in an improved double-shoulder connection 400. The angledprimary shoulder 450 provides an avenue for compressive forces andelevated torques while drilling to move axially and inward into the pinconnection, reducing box swell. The angled primary shoulder 450 alsobalances compressive forces between the primary and secondary shoulderconnections. FIG. 4A illustrates a cross-sectional view of an improveddouble-shoulder connection 400 with an angled primary shoulder 450 and astandard secondary shoulder 460 according to an embodiment of thepresent invention. As shown in FIG. 4A, the improved double-shoulderconnection 400 comprises a box connection 410 having a box axis(centerline) 412, a pin connection 430 having a pin axis (centerline)432, a primary shoulder 450, and a secondary shoulder 460.

In an embodiment, the primary shoulder 450 comprises a primary boxshoulder 452 at a primary box angle 454 with respect to a firstperpendicular 480 to the box axis 412 at a first end point 482 of thebox connection; and a primary pin shoulder 456 at a primary pin angle458 with respect to a first perpendicular 480 to the pin axis 432 at thefirst end point 482 of the pin connection. See also FIG. 1A: 112 & FIG.1B: 132 (showing box and pin made up). In an embodiment, the first endpoint 482 may be equal to a datum intersection, as discussed below.

In an embodiment, the primary box shoulder 452 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary box shoulder 452 maybe conical shaped (outside of cone, male).

In an embodiment, the primary pin shoulder 456 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary pin shoulder 456 maybe conical shaped (inside of cone, female).

In an embodiment, the primary box shoulder 452 may be any suitableprofile. For example, suitable profiles include, but are not limited toangled profiles. In an embodiment, the primary box shoulder 452 may bean angled profile defined by a primary box angle 454, as discussedbelow.

In an embodiment, the primary box angle 454 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary box angle 454 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary box angle 454 may be about 5degrees.

In an embodiment, the primary pin shoulder 456 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary pin shoulder 456 may bean angled profile defined by a primary pin angle 458, as discussedbelow.

In an embodiment, the primary pin angle 458 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary pin angle 458 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary pin angle 458 may be about 5degrees.

In an embodiment, the primary box angle 454 may be about equal to theprimary pin angle 458 to form a first seal.

In an embodiment, the primary box angle 454 may be slightly differentfrom the primary pin angle 458 to form a first seal. In an embodiment,the first seal may be a gas-tight seal.

FIG. 4B illustrates a detailed view E in FIG. 4A, showing the angledprimary shoulder 450 according to an embodiment of the presentinvention. As shown in FIG. 4B, the primary box angle may be fromgreater than about 0 degrees to less than or equal to about 15 degrees,and the primary pin angle may be from greater than about 0 degrees toless than or equal to about 15 degrees. See also FIG. 2B (showing astandard primary shoulder 250).

In an embodiment, the secondary shoulder 460 comprises a secondary boxshoulder 462 at a secondary box angle with respect to a secondperpendicular to the box axis at a second end point of the boxconnection; and a secondary pin shoulder 466 at a secondary pin anglewith respect to the second perpendicular to the pin axis at the secondend point of the pin connection. See also FIG. 1A: 112 & FIG. 1B: 132(showing box and pin made-up).

In an embodiment, the secondary box shoulder 462 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the secondary box shoulder 462 maybe conical shaped (outside of cone, male).

In an embodiment, the secondary pin shoulder 466 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the secondary pin shoulder 466 maybe conical shaped (inside of cone, female).

In an embodiment, the secondary box shoulder 462 may be any suitableprofile. For example, suitable profiles include, but are not limited toangled profiles. In an embodiment, the secondary box shoulder 462 may bean angled profile defined by a secondary box angle, as discussed below.

In an embodiment, the secondary box angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the secondary boxangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the secondary box anglemay be about 5 degrees. In an embodiment, the secondary box angle may beabout 0 degrees. See FIG. 4A-4B.

In an embodiment, the secondary pin shoulder 466 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the secondary pin shoulder 466 may bean angled profile defined by a primary pin angle, as discussed below.

In an embodiment, the secondary pin angle may be from greater than toequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the secondary pinangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the secondary pin anglemay be about 5 degrees. In an embodiment, the secondary pin angle may beabout 0 degrees. See FIGS. 4A-4B.

In a standard secondary shoulder 460, the secondary box angle is 0degrees (i.e., secondary box shoulder 462 is perpendicular to the boxaxis 412) and the secondary pin angle is 0 degrees (i.e., secondary pinshoulder 466 is perpendicular to the pin axis 432).

In an embodiment, the secondary box angle may be about equal to thesecondary pin angle to form a torque shoulder.

In an embodiment, the secondary box angle may be slightly different fromthe secondary pin angle to form a torque shoulder that is a second seal.In an embodiment, the torque shoulder or the second seal may be agas-tight seal.

FIG. 4A illustrates the standard secondary shoulder 460 according to anembodiment of the present invention. As shown in FIG. 4A, the secondarybox angle is 0 degrees; and the secondary pin angle is 0 degrees. Seealso FIG. 2C (showing a standard secondary shoulder).

As discussed above, an angled primary shoulder 450, 550 reduces boxswell (e.g., box materials yields) and provides better alignment of thebox threads 426, 526 and pin threads 446, 546 in an improveddouble-shoulder connection 400, 500. The angled primary shoulder 450,550 provides an avenue for compressive forces and elevated torques whiledrilling to move axially and radially (i.e., inward) into the pinconnection, reducing box swell (e.g., box material yields). The angleprimary shoulder 450, 550 also balances compressive forces between theprimary and secondary shoulder connections. FIG. 5A illustrates across-sectional view of the improved double-shoulder connection 400, 500of FIG. 4A, showing box radial retaining forces and pin radial retainingforces. As shown in FIG. 5A, the angled primary shoulder 450, 550reduces the box swell/yielding forces shown in FIG. 3A. See also FIG. 3A(showing a standard primary shoulder 350). In other words, the boxradial retaining forces generated by the angled primary shoulder 450,550 reduce the box swell/yielding forces, reducing box swell (e.g., boxmaterial yield).

As shown in FIG. 5A, the angled primary shoulder 450, 550 also reducesthe pin collapse forces shown in FIG. 3A. See also. FIG. 3A (showing astandard primary shoulder 350). In other words, the pin radial retainingforces generated by the angled primary shoulder 450, 550 reduce the pincollapse forces, reducing pin collapse.

As discussed with respect to the standard double-shoulder connection,the combination of box swell and pin collapse can lead to misalignmentof the box threads 426, 526 and the pin threads 446, 546, as well aspermanent damage to the box connection 410, 510 and/or the pinconnection 430, 530. See also FIGS. 3A (showing a standard primaryshoulder 350) & 3B (showing misaligned threads 326, 346). FIG. 5Billustrates a detailed view F in FIG. 5A, showing improved threadalignment. As shown in FIG. 5B, the box threads 526 are aligned with thepin threads 546.

FIG. 6A illustrates a cross-sectional view of an improveddouble-shoulder connection 600 with a standard primary shoulder 650 andan angled secondary shoulder 660 according to an embodiment of thepresent invention; and FIG. 7 illustrates a cross-sectional view of animproved double-shoulder connection with an angled primary shoulder andan angled secondary shoulder according to an embodiment of the presentinvention. As shown in FIGS. 6A and 7, the improved double-shoulderconnection 600, 700 comprises a box connection 610, 710 having a boxaxis (centerline) 612, a pin connection 630, 730 having a pin axis(centerline) 632, a primary shoulder 650, 750, and a secondary shoulder660, 760.

In an embodiment, the primary shoulder 650, 750 comprises a primary boxshoulder 652, 752 at a primary box angle with respect to a firstperpendicular to the box axis 612 at a first end point of the boxconnection; and a primary pin shoulder 656, 756 at a primary pin anglewith respect to the first perpendicular to the pin axis 632 at the firstend point of the pin connection. See also FIG. 1A: 112 & FIG. 1B: 132(showing box and pin made-up). In an embodiment, the first end point maybe equal to a datum intersection, as discussed below.

In an embodiment, the primary box shoulder 652, 752 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary box shoulder 752 maybe conical shaped (outside of cone, male).

In an embodiment, the primary pin shoulder 656, 756 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary pin shoulder 756 maybe conical shaped (inside of cone, female).

In an embodiment, the primary box shoulder 652, 752 may be any suitableprofile. For example, suitable profiles include, but are not limited toangled profiles. In an embodiment, the primary box shoulder 652, 752 maybe an angled profile defined by a primary box angle, as discussed below.

In an embodiment, the primary box angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. See FIG. 7. In an embodiment, theprimary box angle may be from greater than or equal to about 0 degreesto less than or equal to about 10 degrees. In an embodiment, the primarybox angle may be about 5 degrees. In an embodiment, the primary boxangle is about 0 degrees. See FIGS. 6A-6B.

In an embodiment, the primary pin shoulder 656, 756 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary pin shoulder 656, 756 maybe an angled profile defined by a primary pin angle, as discussed below.

In an embodiment, the primary pin angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. See FIG. 7. In an embodiment, theprimary pin angle may be from greater than or equal to about 0 degreesto less than or equal to about 10 degrees. In an embodiment, the primarypin angle may be about 5 degrees. In an embodiment, the primary pinangle may be about 0 degrees. See FIGS. 6A-6B.

In a standard primary shoulder 650, the primary box angle is 0 degrees(i.e., primary box shoulder 652 is perpendicular to the box axis 112)and the primary pin angle is 0 degrees (i.e., primary pin shoulder 656is perpendicular to the pin axis 132). See FIGS. 6A-6B.

In an embodiment, the primary box angle may be about equal to theprimary pin angle to form a first seal.

In an embodiment, the primary box angle may be slightly different fromthe primary pin angle to form a first seal. In an embodiment, the firstseal may be a gas-tight seal.

In an embodiment, the secondary shoulder 660, 760 comprises a secondarybox shoulder 662, 762 at a secondary box angle 664 with respect to asecond perpendicular 686 to the box axis 612 at a second end point 688of the box connection; and a secondary pin shoulder 666, 766 at asecondary pin angle 668 with respect to the second perpendicular 686 tothe pin axis 632 at the second end point 688 of the pin connection. Seealso FIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made-up).

In an embodiment, the secondary box shoulder 662, 762 may be anysuitable shape. For example, suitable shapes include, but are notlimited to, conical shaped, cylindrical shaped, conical-cylindricalshaped, and variations thereof. In an embodiment, the secondary shoulder662, 762 may be conical shaped (outside of cone, male).

In an embodiment, the secondary pin shoulder 666, 766 may be anysuitable shape. For example, suitable shapes include, but are notlimited to, conical shaped, cylindrical shaped, conical-cylindricalshaped, and variations thereof. In an embodiment, the secondary pinshoulder 666, 766 may be conical shaped (inside of cone, female).

In an embodiment, the secondary box shoulder 662, 762 may be anysuitable profile. For example, suitable profiles include, but are notlimited to, angled profiles. In an embodiment, the secondary boxshoulder 662, 762 may be an angled profile defined by a secondary boxangle 664, as discussed below.

In an embodiment, the secondary box angle 664 may be from greater thanor equal to about 0 degrees to less than or equal to about 15 degrees,and any range or value there between. See also FIG. 7. In an embodiment,the secondary box angle 664 may be from greater than or equal to about 0degrees to less than or equal to about 10 degrees. In an embodiment, thesecondary box angle 664 may be about 5 degrees.

In an embodiment, the secondary pin shoulder 666, 766 may be anysuitable profile. For example, suitable profiles include, but are notlimited to, angled profiles. In an embodiment, the secondary pinshoulder 666, 766 may be an angled profile defined by a secondary pinangle 668, as discussed below.

In an embodiment, the secondary pin angle 668 may be from greater thanor equal to about 0 degrees to less than or equal to about 15 degrees,and any range or value there between. See also FIG. 7. In an embodiment,the secondary pin angle 668 may be from greater than or equal to about 0degrees to less than or equal to about 10 degrees. In an embodiment, thesecondary pin angle 668 may be about 5 degrees.

In an embodiment, the secondary box angle 664 may be about equal to thesecondary pin angle 668 to form a torque shoulder.

In an embodiment, the secondary box angle 664 may be slightly differentfrom the secondary pin angle 668 to form a torque shoulder. In anembodiment, the torque shoulder may be a gas-tight seal.

FIG. 6B illustrates a detailed view G in FIG. 6A, showing the angledsecondary shoulder 660 according to an embodiment of the presentinvention. As shown in FIG. 6B, the secondary box angle 664 may be fromgreater than or equal to about 0 degrees to less than or equal to about15 degrees; and the secondary pin angle 668 may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees.

As discussed above, an angled secondary shoulder 660 reduces box swell(e.g., box materials yields) in an improved double-shoulder connection600. The angled secondary shoulder 660 provides an avenue forcompressive forces and elevated torques while drilling to move axiallyand radially (i.e., inward) into the pin connection, reducing box swell(e.g., box material yields). The angled secondary shoulder 660 alsobalances compressive forces between the primary and secondary shoulderconnections. FIG. 6A illustrates a cross-sectional view of the improveddouble-shoulder connection 600, showing box radial retaining forces andpin radial retaining forces. As shown in FIG. 6A, the angled secondaryshoulder 660 reduces the box swell/yielding forces shown in FIG. 3A. Seealso FIG. 3A (showing a standard secondary shoulder 360). In otherwords, the box radial retaining forces generated by the angled secondaryshoulder 660 reduce the box swell/yielding forces, reducing box swell(e.g., box material yields).

As shown in FIG. 6A, the angled secondary shoulder 660 also reduces thepin collapse forces shown in FIG. 3A. See also. FIG. 3A (showing astandard secondary shoulder 360). In other words, the pin radialretaining forces generated by the angled secondary shoulder 660 reducethe pin collapse forces, reducing pin nose diving.

As discussed with respect to the standard double-shoulder connection,the combination of box swell and pin collapse can lead to permanentdamage to the box connection 610 and/or the pin connection 630 as shownin FIG. 3A. See also FIG. 3A (showing a standard secondary shoulder360).

In an embodiment, the improved double-shoulder connection 400, 500, 600,700, 1200, 1400 may be made of any suitable material. For example,suitable materials include, but are not limited to, low alloy steels(e.g., 4140, 4145, 4330, etc.), stainless steels (e.g., 17-4, 304, 316,etc.), super alloys (e.g., Inconel), titanium alloys (e.g., Ti-6Al-4V,Ti-6Al-6V-2Sn, etc.), copper alloys (e.g., Beryllium copper), cobaltalloys (e.g., Stellite), aluminum alloys (e.g., 2024, 6061,7075, etc.),and combinations and variations thereof. In an embodiment, the improveddouble-shoulder connection 400, 500, 600, 700, 1200, 1400 may be lowalloy steels or stainless steels.

In an embodiment, the improved double-shoulder connection 400, 500, 600,700, 1200, 1400 may be applied to any suitable product. For example,suitable products include, but are not limited to, drill pipe (DP),heavy weight drill pipe (HWDP), drill collars (DC), pup joints,crossover subs, saver subs, bit subs, float subs, pump-in subs, insideblowout preventers (IBOP), top drive shafts, top drive valves, safetyvalves, kelly valves, hoisting equipment (e.g., lift subs, lift plugs),swivels, fishing tools, mud motors, rotary steerable tools, drill bits,directional drilling bottom hole assembly (BHA) components, measurementwhile drilling (MWD) components, logging while drilling (LWD)components, well cleanout tools (e.g., brushes, magnets), completiontools, and combinations and variations thereof. In an embodiment, theimproved double-shoulder connection 400, 500, 600, 700, 1200, 1400 maybe applied to drill pipe (DP) or heavy weight drill pipe (HWDP) or drillcollars (DC) or pup joints.

In an embodiment, the improved double-shoulder connection 400, 500, 600,700, 1200, 1400 may be applied to any suitable diameter drill pipe (DP).For example, suitable diameter DP includes, but is not limited to, fromabout 2⅜-inch outer diameter (OD) to about 7⅝-inch OD, and any range orvalue there between.

In an embodiment, the improved double-shoulder connection 400, 500, 600,700, 1200, 1400 may be applied to any suitable heavy weight diameterdrill pipe (HWDP). For example, suitable diameter HWDP includes, but isnot limited to, from about 2⅞-inch OD to about 6⅝-inch OD, and any rangeor value there between.

In an embodiment, the improved double-shoulder connection 400, 500, 600,700, 1200, 1400 may be applied to any suitable drill collars (DC). Forexample, suitable diameter DC includes, but is not limited to, fromabout 3⅛-inch OD to about 11-inch OD, and any range or value therebetween.

In an embodiment, the improved double-shoulder connection 400, 500, 600,700, 1200, 1400 may be applied to any suitable pup joints. For example,suitable diameter pup joints includes, but is not limited to, from about2⅜-inch OD to about 7⅝-inch OD, and any range or value there between.

Improved Double-Shoulder Connections with Curved Primary Shoulder and/orSecondary Shoulder

A curved primary shoulder 1750 reduces box swell (e.g., box materialyields) and provides better alignment of the box threads 1726 and pinthreads 1746 in an improved double-shoulder connection 1700. The curvedprimary shoulder 1750 provides an avenue for compressive forces andelevated torques while drilling to move axially and inward into the pinconnection, reducing box swell. The curved primary shoulder 1750 alsobalances compressive forces between the primary and secondary shoulderconnections. FIG. 17A illustrates a cross-sectional view of an improveddouble-shoulder connection 1700 with a curved primary shoulder 1750 anda standard secondary shoulder 1760 according to an embodiment of thepresent invention. As shown in FIG. 17A, the improved double-shoulderconnection 1700 comprises a box connection 1710 having a box axis(centerline) 1712, a pin connection 1730 having a pin axis (centerline)1732, a primary shoulder 1750, and a secondary shoulder 1760.

In an embodiment, the primary shoulder 1750 comprises a primary boxshoulder 1752; and a primary pin shoulder 1756. See also FIG. 1A: 112 &FIG. 1B: 132 (showing box and pin made-up).

Primary Box Shoulder

In an embodiment, the primary box shoulder 1752 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the primary shoulder 1752 may be convex shaped.

In an embodiment, the primary box shoulder 1752 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles, curved profiles and variations thereof. In anembodiment, the primary box shoulder 1752 may be an angled profiledefined by a primary box angle with respect to a first perpendicular1780 to the box axis 1712 at a first end point 1782 of the boxconnection, as discussed below. In an embodiment, the first end point1782 may be equal to a datum intersection, as discussed below.

In an embodiment, the primary box angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the primary boxangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the primary box anglemay be about 5 degrees. In an embodiment, the primary box angle may beabout 0 degrees.

In an embodiment, the primary box shoulder 1752 may be a curved profiledefined by a primary axial box radius height 1790, a primary box centerpoint 1792 and a primary box radius 1794, as discussed below.

In an embodiment, the primary axial box radius height 1790 may be fromabout 0.000 inch to about the length of the primary box radius 1794 ininches, and any range or value there between.

In an embodiment, the primary box center point 1792 may be locatedbetween a box counter bore diameter (i.e., two time a box counter boreradius 118) and a pin bevel diameter (i.e., two times a pin bevel radius136). In an embodiment, the primary box center point 1792 may be abouthalf-way between the box counter bore diameter (i.e., two time a boxcounter bore radius 118) and the pin bevel diameter (i.e., two times apin bevel radius 136). In an embodiment, the primary box center point1792 may be about [(box counter bore diameter (i.e., two times a boxcounter bore radius 118)+pin bevel diameter (i.e., two times a pin bevelradius 136))/2].

In an embodiment, the primary box radius 1794 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches,and any range or value there between.

In an embodiment, the primary box radius 1794 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches,and any range or value there between.

Primary Pin Shoulder

In an embodiment, the primary pin shoulder 1756 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the primary pin shoulder 1756 may be concave shaped.

In an embodiment, the primary pin shoulder 1756 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles, curved profiles, and variations thereof. In anembodiment, the primary pin shoulder 1756 may be an angled profiledefined by a primary pin angle with respect to a first perpendicular1780 to the pin axis 1732 at the first end point 1782 of the pinconnection, as discussed below. In an embodiment, the first end point1782 may be equal to a datum intersection.

In an embodiment, the primary pin angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the primary pinangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the primary pin anglemay be about 5 degrees. In an embodiment, the primary pin angle may beabout 0 degrees.

In an embodiment, the primary pin shoulder 1756 may be a curved profiledefined by a primary axial pin radius height 1796, a primary pin centerpoint 1798 and a primary pin radius 17100, as discussed below.

In an embodiment, the primary axial pin radius height 1796 may be fromabout 0.000 inch to about the length of the primary pin radius 17100 ininches, and any range or value there between.

In an embodiment, the primary axial box radius height 1790 may be aboutequal to the primary axial pin radius height 1796.

In an embodiment, the primary pin center point 1798 may be locatedbetween a box counter bore diameter (i.e., two time a box counter boreradius 118) and a pin bevel diameter (i.e., two times a pin bevel radius136). In an embodiment, the primary pin center point 1798 may be abouthalf-way between the box counter bore diameter (i.e., two times a boxcounter bore radius 118) and the pin bevel diameter (i.e., two times apin bevel radius 136). In an embodiment, the primary pin center point1798 may be about [(box counter bore diameter (i.e., two times a boxcounter bore radius 118)+pin bevel diameter (i.e., two times a pin bevelradius 136))/2].

In an embodiment, the primary box center point 1792 may be about equalto the primary pin center point 1798.

In an embodiment, the primary pin radius 17100 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4 inches,and any range or value there between.

In an embodiment, the primary pin radius 17100 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4 inches,and any range or value there between.

In an embodiment, the primary box angle may be about equal to theprimary pin angle to form a first seal. In an embodiment, the primarybox angle may be slightly different from the primary pin angle to form afirst seal. In an embodiment, the first seal may be a gas-tight seal.

In an embodiment, the primary box radius 1794 may be about equal to theprimary pin radius 17100 to form a first seal. In an embodiment, theprimary box radius 1794 may be slightly different from the primary pinradius 17100 to form a first seal. In an embodiment, the first seal maybe a gas-tight seal.

FIG. 17B illustrates a detailed view E in FIG. 17A, showing the curvedprimary shoulder 1750 according to an embodiment of the presentinvention. As shown in FIG. 17B, the primary box radius 1794 and theprimary pin radius 17100 may be greater than about [(pin bevel diameter(i.e., two times pin bevel radius 136)−box counter bore diameter (i.e.,two times box counter bore radius 118))/4] inches. See also FIG. 2B(showing a standard primary shoulder 250).

In an embodiment, the secondary shoulder 1760 comprises a secondary boxshoulder 1762; and a secondary pin shoulder 1766. See also FIG. 1A: 112& FIG. 1B: 132 (showing box and pin made-up).

Secondary Box Shoulder

In an embodiment, the secondary box shoulder 1762 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the secondary box shoulder 1762 may be conical shaped (outside of cone,male).

In an embodiment, the secondary box shoulder 1762 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles, curved profiles and variations thereof. In anembodiment, the secondary box shoulder 1762 may be an angled profiledefined by a secondary box angle with respect to a second perpendicularto the box axis 1712 at a second end point of the box connection, asdiscussed below.

In an embodiment, the secondary box angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the secondary boxangle may be from greater than or equal to about 0 degrees to less thanor equal to 10 degrees. In an embodiment, the secondary box angle may beabout 5 degrees. In an embodiment, the secondary box angle may be about0 degrees.

In a standard secondary shoulder 1760, the secondary box angle is 0degrees (i.e., secondary box shoulder 1762 is perpendicular to the boxaxis 1712).

In an embodiment, the secondary box shoulder 1762 may be a curvedprofile defined by a secondary axial box radius height, a secondary boxcenter point and a secondary box radius, as discussed below.

In an embodiment, the secondary axial box radius height may be fromabout 0.000 inch to about the length of the secondary box radius ininches, and any range or value there between.

In an embodiment, the secondary box center point may be located betweena pin nose outer diameter (i.e., two times pin nose radius 140) and apin nose inner diameter (i.e., two time pin nose inner radius 240 a),and any range or value there between. In an embodiment, the secondarybox center point may be located about half-way between the pin noseouter diameter (i.e., two times pin nose radius 140) and the pin noseinner diameter (i.e., two times pin nose inner radius 240 a). In anembodiment, the secondary box center point may be about [(pin nose outerdiameter (i.e., two times pin nose radius 140)+pin nose inner diameter(i.e., two times pin nose inner radius 240 a))/2].

In an embodiment, the secondary box radius may be greater than about[(pin nose outer diameter (i.e., two times pin nose radius 140)−pin noseinner diameter (i.e., two times pin nose inner radius 240 a))/4] inches,and any range or value there between.

Secondary Pin Shoulder

In an embodiment, the secondary pin shoulder 1766 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the secondary pin shoulder 1766 may be conical shaped (inside of cone,female).

In an embodiment, the secondary pin shoulder 1766 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles, curved profiles and variations thereof. In anembodiment, the secondary pin shoulder 1766 may be an angled profiledefined by a secondary pin angle with respect to the secondperpendicular to the pin axis 1732 at the second end point of the pinconnection, as discussed below.

In an embodiment, the secondary pin angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the secondary pinangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the secondary pin anglemay be about 5 degrees. In an embodiment, the secondary pin angle may beabout 0 degrees.

In a standard secondary shoulder 1760, the secondary pin angle is 0degrees (i.e., secondary pin shoulder 1766 is perpendicular to the pinaxis 1732).

In an embodiment, the secondary pin shoulder 1766 may be a curvedprofile defined by a secondary axial pin radius height, a secondary pincenter point and a secondary pin radius, as discussed below.

In an embodiment, the secondary axial pin radius height may be fromabout 0.000 inch to about the length of the secondary pin radius ininches, and any range or value there between.

In an embodiment, the secondary axial box radius height may be aboutequal to the secondary axial pin radius height.

In an embodiment, the secondary pin center point may be located betweena pin nose outer diameter (i.e., two times pin nose radius 140) and apin nose inner diameter (i.e., two times pin nose inner radius 240 a),and any range or value there between. In an embodiment, the secondarypin center point may be located about half-way between the pin noseouter diameter (i.e., two times pin nose radius 140) and the pin noseinner diameter (i.e., two times pin nose inner radius 240 a). In anembodiment, the secondary pin center point may be about [(pin nose outerdiameter (i.e., two times pin nose radius 140)+pin nose inner diameter(i.e., two times pin nose inner radius 240 a))/2].

In an embodiment, the secondary box center point may be about equal tothe secondary pin center point.

In an embodiment, the secondary pin radius may be greater than about[(pin nose outer diameter (i.e., two times pin nose radius 140)−pin noseinner diameter (i.e., two times pin nose inner radius 240 a))/4] inches,and any range or value there between.

In an embodiment, the secondary box angle may be about equal to thesecondary pin angle to form a torque shoulder.

In an embodiment, the secondary box angle may be slightly different fromthe secondary pin angle to form a torque shoulder that is a second seal.In an embodiment, the torque shoulder or the second seal may be agas-tight seal.

In an embodiment, the secondary box radius may be about equal to thesecondary pin radius to form a torque shoulder.

In an embodiment, the secondary box radius may be slightly differentfrom the secondary pin radius to form a torque shoulder that is a secondseal. In an embodiment, the torque shoulder or the second seal may be agas-tight seal.

FIG. 17A illustrates the standard secondary shoulder 1760 according toan embodiment of the present invention. As shown in FIG. 17A, thesecondary box angle is 0 degrees; and the secondary pin angle is 0degrees. See also FIG. 2C (showing a standard secondary shoulder).

As discussed above, a curved primary shoulder 1750, 1850 reduces boxswell (e.g., box material yields) and provides better alignment of thebox threads 1726, 1826 and pin threads 1746, 1846 in an improveddouble-shoulder connection 1700, 1800. The curved primary shoulder 1750,1850 provides an avenue for compressive forces and elevated torqueswhile drilling to move axially and radially (i.e., inward) into the pinconnection, reducing box swell (e.g., box material yields). The curvedprimary shoulder 1750, 1850 also balances compressive forces between theprimary and secondary shoulder connections. FIG. 18A illustrates across-sectional view of the improved double-shoulder connection 1700,1800 of FIG. 17A, showing box radial retaining forces and pin radialretaining forces. As shown in FIG. 18A, the curved primary shoulder1750, 1850 reduces the box swell/yielding forces shown in FIG. 3A. Seealso FIG. 3A (showing a primary shoulder 350). In other words, the boxradial retaining forces generated by the curved primary shoulder 1750,1850 reduce box swell/yielding forces, reducing box swell (e.g., boxmaterial yields).

FIG. 19A illustrates a cross-sectional view of an improveddouble-shoulder connection 1900 with a standard primary shoulder 1950and a curved secondary shoulder 1960 according to an embodiment of thepresent invention; and FIG. 20 illustrates a cross-sectional view of animproved double-shoulder connection with a curved primary shoulder and acurved secondary shoulder according to an embodiment of the presentinvention. As shown in FIGS. 19A and 20, the improved double-shoulderconnection 1900, 2000 comprises a box connection 1910, 2010 having a boxaxis (centerline) 1912, a pin connection 1930, 2030 having a pin axis(centerline) 1932, a primary shoulder 1950, 2050, and a secondaryshoulder 1960, 2060.

In an embodiment, the primary shoulder 1950, 2050 comprises a primarybox shoulder 1952, 2052; and a primary pin shoulder 1956, 2056. See alsoFIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made-up).

Primary Box Shoulder

In an embodiment, the primary box shoulder 1952, 2052 may be anysuitable shape. For example, suitable shapes include, but are notlimited to, concave shaped, conical shaped, convex shaped, cylindricalshaped, conical-cylindrical shaped, and variations thereof. In anembodiment, the primary box shoulder 1952 may be conical shaped (outsideof cone, male). In an embodiment, the primary box shoulder 2052 may beconvex shaped.

In an embodiment, the primary box shoulder 1952, 2052 may be anysuitable profile. For example, suitable profiles include, but are notlimited to, angled profiles, curved profiles, and variations thereof. Inan embodiment, the primary box shoulder 1952 may be an angled profiledefined by a primary box angle with respect to a first perpendicular tothe box axis 1912 at a first end point of the box connection, asdiscussed below. In an embodiment, the first end point may be equal to adatum intersection.

In an embodiment, the primary box angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the primary boxangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the primary box anglemay be about 5 degrees. In an embodiment, the primary box angle may beabout 0 degrees.

In an embodiment, the primary box shoulder 2052 may be a curved profiledefined by a primary axial box radius height, a primary box center pointand a primary box radius, as discussed below.

In an embodiment, the primary axial box radius height may be from about0.000 inch to about the length of the primary box radius in inches, andany range or value there between.

In an embodiment, the primary box center point may be located between abox counter bore diameter (i.e., two times a box counter bore radius118) and a pin bevel diameter (i.e., two times a pin bevel radius 136).In an embodiment, the primary box center point may be about half-waybetween the box counter bore diameter (i.e., two times a box counterbore radius 118) and the pin bevel diameter (i.e., two times a pin bevelradius 136). In an embodiment, the primary box center point may be about[(box counter bore diameter (i.e., two times a box counter bore radius118)+pin bevel diameter (i.e., two times a pin bevel radius 136))/2].

In an embodiment, the primary box radius may be greater than about [(pinbevel diameter (i.e., two times pin bevel radius 136)−box counter borediameter (i.e., two times box counter bore radius 118))/4] inches, andany range or value there between.

In an embodiment, the primary box radius may be greater than about [(pinbevel diameter (i.e., two times pin bevel radius 166)−box counter borediameter (i.e., two times box counter bore radius 118))/4] inches, andany range or value there between.

Primary Pin Shoulder

In an embodiment, the primary pin shoulder 1956, 2056 may be anysuitable shape. For example, suitable shapes include, but are notlimited to, concave shaped, conical shaped, convex shaped, cylindricalshaped, conical-cylindrical shaped, and variations thereof. In anembodiment, the primary pin shoulder 1956 may be conical shaped (insideof cone, female). In an embodiment, the primary pin shoulder 2065 may beconcave shaped.

In an embodiment, the primary pin shoulder 1956, 2056 may be anysuitable profile. For example, suitable profiles include, but are notlimited to, angled profiles, curved profiles, and variations thereof. Inan embodiment, the primary pin shoulder 1956 may be an angled profiledefined by a primary pin angle with respect to the first perpendicularto the pin axis 1932 at the first end point of the pin connection, asdiscussed below. In an embodiment, the first end point may be equal to adatum intersection.

In an embodiment, the primary pin angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the primary pinangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the primary pin anglemay be about 5 degrees. In an embodiment, the primary pin angle may beabout 0 degrees.

In an embodiment, the primary pin shoulder 2056 may be a curved profiledefined by a primary axial pin radius height, a primary pin center pointand a primary pin radius, as discussed below.

In an embodiment, the primary pin axial pin radius height may be fromabout 0.000 inch to about the length of the primary pin radius ininches, and any range or value there between.

In an embodiment, the primary axial box radius height may be about equalto the primary axial pin radius height.

In an embodiment, the primary pin center point may be located between abox counter bore diameter (i.e., two times a box counter bore radius118) and a pin bevel diameter (i.e., two times a pin bevel radius 136).In an embodiment, the primary pin center point may be about half-waybetween the box counter bore diameter (i.e., two times a box counterbore radius 118) and the pin bevel diameter (i.e., two times a pin bevelradius 136). In an embodiment, the primary pin center point may be about[(box counter bore diameter (i.e., two times a box counter bore radius118)+pin bevel diameter (i.e., two times a pin bevel radius 136))/2].

In an embodiment, the primary pin radius may be greater than about [(pinbevel diameter (i.e., two times pin bevel radius 136)−box counter borediameter (i.e., two times box counter bore radius 118))/4] inches, andany range or value there between.

In an embodiment, the primary pin radius may be greater than about [(pinbevel diameter (i.e., two times pin bevel radius 136)−box counter borediameter (i.e., two times box counter bore radius 118))/4] inches, andany range or value there between.

In an embodiment, the primary box angle may be about equal to theprimary pin angle to form a first seal. In an embodiment, the primarybox angle may be slightly different from the primary pin angle to form afirst seal. In an embodiment, the first seal may be a gas-tight seal.

In an embodiment, the primary box center point may be about equal to theprimary pin center point.

In an embodiment, the primary box radius may be about equal to theprimary pin radius to form a first seal. In an embodiment, the primarybox radius may be slightly different from the primary pin radius to forma first seal. In an embodiment, the first seal may be a gas-tight seal.

In an embodiment, the secondary shoulder 1960, 2060 comprises asecondary box shoulder 1962, 2062; and a secondary pin shoulder 1966,2066. See also FIG. 1A: 112 & FIG. 1B: 132 (showing box and pinmade-up).

Secondary Box Shoulder

In an embodiment, the secondary box shoulder 1962, 2062 may be anysuitable shape. For example, suitable shapes include, but are notlimited to, concave shaped, conical shaped, convex shaped, cylindricalshaped, conical-cylindrical shaped, and variations thereof. In anembodiment, the secondary box shoulder 1962, 2062 may be concave shaped.

In an embodiment, the secondary box shoulder 1962, 2062 may be anysuitable profile. For example, suitable profiles include, but are notlimited to, angled profiles, curved profiles, and variations thereof. Inan embodiment, the secondary box shoulder 1962, 2062 may be an angledprofile defined by a secondary box angle with respect to a secondperpendicular 1986 to the box axis 1912 at a second end point 1988 ofthe box connection, as discussed below.

In an embodiment, the secondary box angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the secondary boxangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the secondary box anglemay be about 5 degrees. In an embodiment, the secondary box angle may beabout 0 degrees.

In an embodiment, the secondary box shoulder 1962, 2062 may be a curvedprofile defined by a secondary box axial box radius height 19102, asecondary box center point 19104 and a secondary box radius 19106, asdiscussed below.

In an embodiment, the secondary axial box radius height 19102 may befrom about 0.000 inch to about the length of the primary box radius19106 in inches, and any range or value there between.

In an embodiment, the secondary box center point 19104 may be locatedbetween a pin nose outer diameter (i.e., two times pin nose radius 140)and a pin nose inner diameter (i.e., two times pin nose inner radius 240a), and any range or value there between. In an embodiment, thesecondary box center point 19104 may be located about half-way between apin nose outer diameter (i.e., two times pin nose radius 140) and a pinnose inner diameter (i.e., two times pin nose inner radius 240 a). In anembodiment, the secondary box center point 19104 may be about [(pin noseouter diameter (i.e., two times pin nose radius 140)+pin nose innerdiameter (i.e., two time pin nose inner radius 240 a))/2].

In an embodiment, the secondary box radius 19106 may be greater thanabout [(pin nose outer diameter (i.e., two times pin nose radius140)−pin nose inner diameter (i.e., two times pin nose inner radius 240a))/4] inches, and any range or value there between.

Secondary Pin Shoulder

In an embodiment, the secondary pin shoulder 1966, 2066 may be anysuitable shape. For example, suitable shapes include, but are notlimited to, concave shaped, conical shaped, convex shaped, cylindricalshaped, conical-cylindrical shaped, and variations thereof. In anembodiment, the secondary pin shoulder 1966, 2066 may be convex shaped.

In an embodiment, the secondary pin shoulder 1966, 2066 may be anysuitable profile. For example, suitable profiles include, but are notlimited to, angled profiles, curved profiles, and variations thereof. Inan embodiment, the secondary pin shoulder 1966, 2066 may be an angledprofile defined by a secondary pin angle with respect to the secondperpendicular 1986 to the pin axis 1932 at the second end point 1988 ofthe pin connection, as discussed below.

In an embodiment, the secondary pin angle may be from greater than orequal to about 0 degrees to less than or equal to about 15 degrees, andany range or value there between. In an embodiment, the secondary pinangle may be from greater than or equal to about 0 degrees to less thanor equal to about 10 degrees. In an embodiment, the secondary pin anglemay be about 5 degrees. In an embodiment, the secondary pin angle may beabout 0 degrees.

In an embodiment, the secondary pin shoulder 1966, 2066 may be a curvedprofile defined by a secondary axial pin radius height 19106, asecondary pin center point 19110 and a secondary pin radius 19112, asdiscussed below.

In an embodiment, the secondary axial pin radius height 19108 may befrom about 0.000 inch to about the length of the secondary pin radius19112 in inches, and any range or value there between.

In an embodiment, the secondary axial box radius height 19102 may beabout equal to the secondary axial pin radius height 19108.

In an embodiment, the secondary pin center point 19110 may be locatedbetween a pin nose outer diameter (i.e., two times pin nose radius 140)and a pin nose inner diameter (i.e., two times pin nose inner radius 240a), and any range or value there between. In an embodiment, thesecondary pin center point 19110 may be located about half-way between apin nose outer diameter (i.e., two times pin nose radius 140) and a pinnose inner diameter (i.e., two times pin nose inner radius 240 a). In anembodiment, the secondary pin center point 19110 may be about [(pin noseouter diameter (i.e., two times pin nose radius 140)+pin nose innerdiameter (i.e., two times pin nose inner radius 240 a))/2].

In an embodiment, the secondary pin radius 19112 may be greater thanabout [(pin nose outer diameter (i.e., two times pin nose radius140)−pin nose inner diameter (i.e., two times pin nose inner radius 240a))/4] inches, and any range or value there between.

In an embodiment, the secondary box angle may be about equal to thesecondary pin angle to form a torque shoulder.

In an embodiment, the secondary box angle may be slightly different fromthe secondary pin angle to form a torque shoulder that is a second seal.In an embodiment, the torque shoulder or the second seal may be agas-tight seal.

In an embodiment, the secondary box center point 19104 may be aboutequal to the secondary pin center point 19110.

In an embodiment, the secondary box radius 19106 may be about equal tothe secondary pin radius 19112 to form a torque shoulder.

In an embodiment, the secondary box radius 19106 may be slightlydifferent from the secondary pin radius 19112 to form a torque shoulderthat is a second seal. In an embodiment, the torque shoulder or thesecond seal may be a gas-tight seal.

FIG. 19B illustrates a detailed view G in FIG. 19A, showing the curvedsecondary shoulder 1960 according to an embodiment of the presentinvention. As shown in FIG. 19B, the secondary box radius 19106 and thesecondary pin radius 19112 may be greater than about [(pin nose outerdiameter (i.e., two times pin nose radius 140)−pin nose inner diameter(i.e., two times pin nose inner radius 240 a))/4] inches, and any rangeor value there between. See also FIG. 2C (showing a standard secondaryshoulder 260).

As discussed above, a curved secondary shoulder 1960 reduces box swell(e.g., box material yields) in an improved double-shoulder connection1900. The curved secondary shoulder 1960 provides an avenue forcompressive forces and elevated torques while drilling to move axiallyand radially (i.e., inward) into the pin connection, reducing box swell(e.g., box material yields). The curved secondary shoulder 1960 alsobalances compressive forces between the primary and secondary shoulderconnections. FIG. 19A illustrates a cross-sectional view of the improveddouble-shoulder connection 1900, showing box radial retaining forces andpin radial retaining forces. As shown in FIG. 19A, the curved secondaryshoulder 1960 reduces the box swell/yielding forces shown in FIG. 3A.See also FIG. 3A (showing standard secondary shoulder 360). In otherwords, the box radial retaining forces generated by the curved secondaryshoulder 1960 reduce the box swell/yielding forces, reducing box swell(e.g., box material yields).

As shown in FIG. 19A, a curved secondary shoulder 1960 also reduces thepin collapse forces shown in FIG. 3A. See also FIG. 3A (showing astandard secondary shoulder 360). In other words, the pin radialretaining forces generated by the curved secondary shoulder 1960 reducethe pin collapse forces, reducing pin nose diving.

As discussed with respect to the standard double-shoulder connection,the combination of box swell and pin collapse can lead to permanentdamage to the box connection 1910 and/or the pin connection 1930. Seealso FIG. 3A (showing a standard secondary shoulder 360).

In an embodiment, the improved double-shoulder connection 1700, 1800,1900, 2000, 2400, 2600 may be made of any suitable material. Forexample, suitable materials include, but are not limited to, low alloysteels (e.g., 4140, 4145, 4330, etc.), stainless steels (e.g., 17-4,304, 316, etc.), super alloys (e.g., Inconel), titanium alloys (e.g.,Ti-6Al-4V, Ti-6Al-6V-2Sn, etc.), copper alloys (e.g., Beryllium copper),cobalt alloys (e.g., Stellite), aluminum alloys (e.g., 2024, 6061,7075,etc.), and combinations and variations thereof. In an embodiment, theimproved double-shoulder connection 1700, 1800, 1900, 2000, 2400, 2600may be low alloy steels or stainless steels.

In an embodiment, the improved double-shoulder connection 1700, 1800,1900, 2000, 2400, 2600 may be applied to any suitable product. Forexample, suitable products include, but are not limited to, drill pipe(DP), heavy weight drill pipe (HWDP), drill collars (DC), pup joints,crossover subs, saver subs, bit subs, float subs, pump-in subs, insideblowout preventers (IBOP), top drive shafts, top drive valves, safetyvalves, kelly valves, hoisting equipment (e.g., lift subs, lift plugs),swivels, fishing tools, mud motors, rotary steerable tools, drill bits,directional drilling bottom hole assembly (BHA) components, measurementwhile drilling (MWD) components, logging while drilling (LWD)components, well cleanout tools (e.g., brushes, magnets), completiontools, and combinations and variations thereof. In an embodiment, theimproved double-shoulder connection 1700, 1800, 1900, 2000, 2400, 2600may be applied to drill pipe (DP) or heavy weight drill pipe (HWDP) ordrill collars (DC) or pup joints.

In an embodiment, the improved double-shoulder connection 1700, 1800,1900, 2000, 2400, 2600 may be applied to any suitable diameter drillpipe (DP). For example, suitable diameter DP includes, but is notlimited to, from about 2⅜-inch outer diameter (OD) to about 7⅝-inch OD,and any range or value there between.

In an embodiment, the improved double-shoulder connection 1700, 1800,1900, 2000, 2400, 2600 may be applied to any suitable heavy weightdiameter drill pipe (HWDP). For example, suitable diameter HWDPincludes, but is not limited to, from about 2⅞-inch OD to about 6⅝-inchOD, and any range or value there between.

In an embodiment, the improved double-shoulder connection 1700, 1800,1900, 2000, 2400, 2600 may be applied to any suitable drill collars(DC). For example, suitable diameter DC includes, but is not limited to,from about 3⅛-inch OD to about 11-inch OD, and any range or value therebetween.

In an embodiment, the improved double-shoulder connection 1700, 1800,1900, 2000, 2400, 2600 may be applied to any suitable pup joints. Forexample, suitable diameter pup joints includes, but is not limited to,from about 2⅜-inch OD to about 7⅝-inch OD, and any range or value therebetween.

Improved Single-Shoulder Connections with Angled Primary Shoulder

Similar to the double-shoulder connections 400, 500, 600, 700, 1200,1400 discussed above, an angled primary shoulder 850, 950, 1050, 1250reduces box swell (e.g., box material yields) and provides betteralignment of the box threads 826, 926, 1026 and pin threads 846, 946,1046 in an improved single-shoulder connection 800, 900, 1000, 1200. Theangled primary shoulder 850, 950, 1050 provides an avenue forcompressive forces and elevated torques while drilling to move axiallyand radially (i.e., inward) into the pin connection, reducing box swell.FIGS. 8A, 9 and 10 illustrate a cross-sectional view of an improvedsingle-shoulder connection 800, 900, 1000 with an angled primaryshoulder 850, 950, 1050 according to an embodiment of the presentinvention. As shown in FIGS. 8A, 9 and 10, the improved single-shoulderconnection 800, 900, 1000 comprises a box connection 810, 910, 1010having a box axis (centerline) 812, a pin connection 830, 930, 1030having a pin axis (centerline) 832, and a primary shoulder 850, 950,1050.

In an embodiment, the primary shoulder 850 comprises a primary boxshoulder 852 at a primary box angle 854 with respect to a firstperpendicular 880 to the box axis 812 at a first end point 882 of thebox connection; and a primary pin shoulder 856 at a primary pin angle858 with respect to the first perpendicular 880 to the pin axis 832 atthe first end point 882 of the pin connection. See also FIG. 1A: 112 &FIG. 1B: 132 (showing box and pin made-up). In an embodiment, the firstend point 882 may be equal to a datum intersection, as discussed below.

In an embodiment, the primary box shoulder 852 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary shoulder 852 may beconical shaped (outside of cone, male).

In an embodiment, the primary pin shoulder 856 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary pin shoulder 856 maybe conical shaped (inside of cone, female).

In an embodiment, the primary box shoulder 852 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary box shoulder 852 may bean angled profile defined by a primary box angle 854, as discussedbelow.

In an embodiment, the primary box angle 854 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary box angle 854 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary box angle 854 may be about 5degrees.

In an embodiment, the primary pin shoulder 856 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary pin shoulder 856 may bean angled profile defined by a primary pin angle 858, as discussedbelow.

In an embodiment, the primary pin angle 858 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary pin angle 858 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary pin angle 858 may be about 5degrees.

In an embodiment, the primary box angle 854 may be about equal to theprimary pin angle 858 to form a first seal.

In an embodiment, the primary box angle 854 may be slightly differentfrom the primary pin angle 858 to form a first seal. In an embodiment,the first seal may be a gas-tight seal.

FIG. 8B illustrates a detailed view H in FIG. 8A, showing the angledprimary shoulder 850 according to an embodiment of the presentinvention. As shown in FIG. 8B, the primary box angle 854 may be fromgreater than about 0 degrees to less than or equal to about 15 degrees;and the primary pin angle 858 may be from greater than about 0 degreesto less than or equal to about 15 degrees. See also FIG. 2B (showing astandard primary shoulder 250).

In an embodiment, the improved single-shoulder connection 800, 900,1000, 1200 may be made of any suitable material. For example, suitablematerials include, but are not limited to, low alloy steels (e.g., 4140,4145, 4330, etc.), stainless steels (e.g., 17-4, 304, 316, etc.), superalloys (e.g., Inconel), titanium alloys (e.g., Ti-6Al-4V, Ti-6Al-6V-2Sn,etc.), copper alloys (e.g., Beryllium copper), cobalt alloys (e.g.,Stellite), aluminum alloys (e.g., 2024, 6061,7075, etc.), andcombinations and variations thereof. In an embodiment, the improvedsingle-shoulder connection 800, 900, 1000, 1200 may be low alloy steelsor stainless steels.

In an embodiment, the improved single-shoulder connection 800, 900,1000, 1200 may be applied to any suitable product. For example, suitableproducts include, but are not limited to, drill pipe (DP), heavy weightdrill pipe (HWDP), drill collars (DC), pup joints, crossover subs, saversubs, bit subs, float subs, pump-in subs, inside blowout preventers(IBOP), top drive shafts, top drive valves, safety valves, kelly valves,hoisting equipment (e.g., lift subs, lift plugs), swivels, fishingtools, mud motors, rotary steerable tools, drill bits, directionaldrilling bottom hole assembly (BHA) components, measurement whiledrilling (MWD) components, logging while drilling (LWD) components, wellcleanout tools (e.g., brushes, magnets), completion tools andcombinations and variations thereof. In an embodiment, the improvedsingle-shoulder connection 800, 900, 1000, 1200 may be applied to drillpipe (DP) or heavy weight drill pipe (HWDP) or drill collars (DC) or pupjoints.

In an embodiment, the improved single-shoulder connection 800, 900,1000, 1200 may be applied to any suitable diameter drill pipe (DP). Forexample, suitable diameter DP include, but are not limited to, fromabout 2⅜-inch outer diameter (OD) to about 7⅝-inch OD, and any range orvalue there between.

In an embodiment, the improved single-shoulder connection 800, 900,1000, 1200 may be applied to any suitable heavy weight diameter drillpipe (HWDP). For example, suitable diameter HWDP include, but are notlimited to, from about 2⅞-inch OD to about 6⅝-inch OD, and any range orvalue there between.

In an embodiment, the improved single-shoulder connection 800, 900,1000, 1200 may be applied to any suitable drill collars (DC). Forexample, suitable diameter DC include, but are not limited to, fromabout 3⅛-inch OD to about 11-inch OD, and any range or value therebetween.

In an embodiment, the improved single-shoulder connection 800, 900,1000, 1200 may be applied to any suitable pup joints. For example,suitable diameter pup joints include, but are not limited to, from about2⅜-inch OD to about 7⅝-inch OD, and any range or value there between.

Improved Single-Shoulder Connections with Curved Primary Shoulder

Similar to the double-shoulder connections 1700, 1800, 1900, 2000, 2400,2600, discussed above, a curved primary shoulder 2150, 2250, 2350, 2450reduces box swell (e.g., box material yields) and provides betteralignment of the box threads 2126, 2226, 2326 and pin threads 2146,2246, 2346 in an improved single-shoulder connection 2100, 2200, 2300,2400. The curved primary shoulder 2150, 2250, 2350 provides an avenuefor compressive forces and elevated torques while drilling to moveaxially and radially (i.e., inward) into the pin connection, reducingbox swell. FIGS. 21A, 22 and 23 illustrate a cross-sectional view of animproved single-shoulder connection 2100, 2200, 2300 with a curvedprimary shoulder 2150, 2250, 2350 according to an embodiment of thepresent invention. As shown in FIGS. 21A, 22 and 23, the improvedsingle-shoulder connection 2100, 2200, 2300 comprises a box connection2110, 2210, 2310 having a box axis (centerline) 2112, a pin connection2130, 2230, 2330 having a pin axis (centerline) 2132, and a primaryshoulder 2150,22950, 2350.

In an embodiment, the primary shoulder 2150 comprises a primary boxshoulder 2152; and a primary pin shoulder 2156. See also FIG. 1A: 112 &FIG. 1B: 132 (showing box and pin made-up).

Primary Box Shoulder

In an embodiment, the primary box shoulder 2152 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, convex shaped, and variations thereof. In an embodiment,the primary shoulder 2152 may be convex shaped.

In an embodiment, the primary box shoulder 2152 may be any suitableprofile. For example, suitable profiles include, but are not limited to,curved profiles, and variations thereof. In an embodiment, the primarybox shoulder 2152 may be a curved profile defined by a primary axial boxradius height 2190, a primary box center point 2192 and a primary boxradius 2194, as discussed below.

In an embodiment, the primary axial box radius height 2190 may be fromabout 0.000 inch to about the length of the primary box radius 2194 ininches, and any range or value there between.

In an embodiment, the primary box center point 2192 may be locatedbetween a box counter bore diameter (i.e., two times a box counter boreradius 118) and a pin bevel diameter (i.e., two times a pin bevel radius136). In an embodiment, the primary box center point 2192 may be abouthalf-way between the box counter bore diameter (i.e., two times a boxcounter bore radius 118) and the pin bevel diameter (i.e., two times apin bevel radius 136). In an embodiment, the primary box center point2192 may be about [(box counter bore diameter (i.e., two times a boxcounter bore radius 118)+pin bevel diameter (i.e., two times a pin bevelradius 136))/2].

In an embodiment, the primary box radius 2194 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches,and any range or value there between.

In an embodiment, the primary box radius 2194 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches,and any range or value there between.

Primary Pin Shoulder

In an embodiment, the primary pin shoulder 2156 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, convex shaped, and variations thereof. In an embodiment,the primary pin shoulder 2156 may be concave shaped.

In an embodiment, the primary pin shoulder 2156 may be any suitableprofile. For example, suitable profiles include, but are not limited to,curved profiles, and variations thereof. In an embodiment, the primarypin shoulder 2156 may be a curved profile defined by a primary axial pinradius height 2196, a primary pin center point 2198 and a primary pinradius 21100, as discussed below.

In an embodiment, the primary axial pin radius height 2196 may be fromabout 0.000 inch to about the length of the primary pin radius 21100 ininches, and any range or value there between.

In an embodiment, the primary pin center point 2198 may be locatedbetween a box counter bore diameter (i.e., two times a box counter boreradius 118) and a pin bevel diameter (i.e., two times a pin bevel radius136). In an embodiment, the primary pin center point 2198 may be abouthalf-way between the box counter bore diameter (i. e., two times a boxcounter bore radius 118) and the pin bevel diameter (i.e., two times apin bevel radius 136). In an embodiment, the primary pin center point2198 may be about [(box counter bore diameter (i.e., two times a boxcounter bore radius 118)+pin bevel diameter (i.e., two times a pin bevelradius 136))/2].

In an embodiment, the primary pin radius 21100 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches,and any range or value there between.

In an embodiment, the primary pin radius 21100 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches,and any range or value there between.

In an embodiment, the primary box center point 2192 may be about equalto the primary pin center point 2198.

In an embodiment, the primary box radius 2194 may be about equal to theprimary pin radius 21100 to form a first seal. In an embodiment, theprimary box radius 2194 may be slightly different from the primary pinradius 21100 to form a first seal. In an embodiment, the first seal maybe a gas-tight seal.

FIG. 21B illustrates a detailed view H in FIG. 21A, showing the curvedprimary shoulder 2150 according to an embodiment of the presentinvention. As shown in FIG. 21B, the primary box radius 2194 and theprimary pin radius 21100 may be greater than about [(pin bevel diameter(i.e., two times pin bevel radius 136)−box counter bore diameter (i.e.,two times box counter bore radius 118))/4] inches. Cf. FIG. 2B (showinga standard primary shoulder 250).

In an embodiment, the improved single-shoulder connection 2100, 2200,2300, 2400 may be made of any suitable material. For example, suitablematerials include, but are not limited to, low alloy steels (e.g., 4140,4145, 4330, etc.), stainless steels (e.g., 17-4, 304, 316, etc.), superalloys (e.g., Inconel), titanium alloys (e.g., Ti-6Al-4V, Ti-6Al-6V-2Sn,etc.), copper alloys (e.g., Beryllium copper), cobalt alloys (e.g.,Stellite), aluminum alloys (e.g., 2024, 6061,7075, etc.), andcombinations and variations thereof. In an embodiment, the improvedsingle-shoulder connection 2100, 2200, 2300, 2400 may be low alloysteels or stainless steels.

In an embodiment, the improved single-shoulder connection 2100, 2200,2300, 2400 may be applied to any suitable product. For example, suitableproducts include, but are not limited to, drill pipe (DP), heavy weightdrill pipe (HWDP), drill collars (DC), pup joints, crossover subs, saversubs, bit subs, float subs, pump-in subs, inside blowout preventers(IBOP), top drive shafts, top drive valves, safety valves, kelly valves,hoisting equipment (e.g., lift subs, lift plugs), swivels, fishingtools, mud motors, rotary steerable tools, drill bits, directionaldrilling bottom hole assembly (BHA) components, measurement whiledrilling (MWD) components, logging while drilling (LWD) components, wellcleanout tools (e.g., brushes, magnets), completion tools andcombinations and variations thereof. In an embodiment, the improvedsingle-shoulder connection 2100, 2200, 2300, 2400 may be applied todrill pipe (DP) or heavy weight drill pipe (HWDP) or drill collars (DC)or pup joints.

In an embodiment, the improved single-shoulder connection 2100, 2200,2300, 2400 may be applied to any suitable diameter drill pipe (DP). Forexample, suitable diameter DP include, but are not limited to, fromabout 2⅜-inch outer diameter (OD) to about 7⅝-inch OD, and any range orvalue there between.

In an embodiment, the improved single-shoulder connection 2100, 2200,2300, 2400 may be applied to any suitable heavy weight diameter drillpipe (HWDP). For example, suitable diameter HWDP include, but are notlimited to, from about 2⅞-inch OD to about 6⅝-inch OD, and any range orvalue there between.

In an embodiment, the improved single-shoulder connection 2100, 2200,2300, 2400 may be applied to any suitable drill collars (DC). Forexample, suitable diameter DC include, but are not limited to, fromabout 3⅛-inch OD to about 11-inch OD, and any range or value therebetween.

In an embodiment, the improved single-shoulder connection 2100, 2200,2300, 2400 may be applied to any suitable pup joints. For example,suitable diameter pup joints include, but are not limited to, from about2⅜-inch OD to about 7⅝-inch OD, and any range or value there between.

Optional Box Stress Relief Groove and/or Pin Stress Relief Groove withImproved Double-Shoulder Connections with Angled Primary Shoulder and/orSecondary Shoulder

An optional box stress relief groove 980 and/or an optional pin stressrelief groove 990 may be applied to a double-shoulder connection 400,500, 600, 700, 1200, 1400 or a single-shoulder connection 800, 900,1000, 1200 at portion(s) where premature fatigue failure of thedouble-shoulder connection or the single-shoulder connection may occuras a result of alternating axial, torsional and bending loads, asdiscussed above with respect to FIGS. 2A-3B.

FIG. 9 illustrates a cross-sectional view of an improved single-shoulderconnection 900 with an optional box stress relief groove 980 and anoptional pin stress relief groove 990 according to an embodiment of thepresent invention. As shown in FIG. 9, the optional box stress reliefgroove 980 and/or the optional pin stress relief groove 990 removesunengaged threads in potentially stressed portions of thesingle-shoulder connection 900 so that any bending occurs in portionswith smooth surfaces that are relatively free of stress concentrations.

Similar to FIG. 8A, FIG. 9 illustrates a cross-sectional view of animproved single-shoulder connection 900 with an angled primary shoulder950 according to an embodiment of the present invention. As shown inFIGS. 8 and 9, the improved single-shoulder connection 800, 900comprises a box connection 810, 910 having a box axis (centerline) 812,a pin connection 830, 930 having a pin axis (centerline) 832, and aprimary shoulder 850, 950.

In an embodiment, the primary shoulder 850, 950 comprises a primary boxshoulder 852, 952 at a primary box angle 854 with respect to a firstperpendicular 880 to the box axis 812 at a first end point 882 of thebox connection; and a primary pin shoulder 856, 956 at a primary pinangle 858 with respect to the first perpendicular 880 to the pin axis832 at the first end point 882 of the pin connection. See also FIG. 1A:112 & FIG. 1B: 132 (showing box and pin made-up). In an embodiment, thefirst end point 882 may be equal to a datum intersection, as discussedbelow.

Optional Box Stress Relief Groove and/or Pin Stress Relief Groove withImproved Double-Shoulder Connections with a Curved Primary Shoulderand/or Secondary Shoulder

An optional box stress relief groove 2280 and/or an optional pin stressrelief groove 2290 may be applied to a double-shoulder connection 1700,1800, 1900, 2000, 2400, 2600 or a single-shoulder connection 2100, 2200,2300, 2400 at portion(s) where premature fatigue failure of thedouble-shoulder connection or the single-shoulder connection may occuras a result of alternating axial, torsional and bending loads, asdiscussed above with respect to FIGS. 2A-3B.

FIG. 22 illustrates a cross-sectional view of an improvedsingle-shoulder connection 2200 with an optional box stress reliefgroove 2280 and an optional pin stress relief groove 2290 according toan embodiment of the present invention. As shown in FIG. 22, theoptional box stress relief groove 2280 and/or the optional pin stressrelief groove 2290 removes unengaged threads in potentially stressedportions of the single-shoulder connection 2200 so that any bendingoccurs in portions with smooth surfaces that are relatively free ofstress concentrations.

Similar to FIG. 21A, FIG. 22 illustrates a cross-sectional view of animproved single-shoulder connection 2200 with a curved primary shoulder2250 according to an embodiment of the present invention. As shown inFIGS. 21 and 22, the improved single-shoulder connection 2100, 2200comprises a box connection 2110, 2210 having a box axis (centerline)2112, a pin connection 2130, 2230 having a pin axis (centerline) 2132,and a primary shoulder 2150, 2250.

In an embodiment, the curved primary shoulder 2150, 2250 comprises aprimary box shoulder 2152, 2252; and a primary pin shoulder 2156, 2256.See also FIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made-up).

Optional Box Boreback and Pin Stress Relief Groove with ImprovedSingle-Shoulder Connections with Angled Primary Shoulder

An optional box boreback 1070 may be applied to a single-shoulderconnection 800, 900, 1000, 1200 at portion(s) where fatigue may occur asa result of bending; and an optional pin stress relief groove 1090 maybe applied to a double-shoulder connection 400, 500, 600, 700, 1200,1400 or a single-shoulder connection 800, 900, 1000, 1200 at portion(s)where fatigue may occur as a result of bending. FIG. 10 illustrates across-sectional view of an improved single-shoulder connection with anoptional box boreback 1070 and an optional pin stress relief groove 1090according to an embodiment of the present invention. As shown in FIG.10, the optional box boreback 1070 and/or the optional pin stress reliefgroove 1090 removes unengaged threads in potentially stressed portionsof the single-shoulder connection 1000 so that any bending occurs inportions with smooth surfaces that are relatively free of stressconcentrations.

Similar to FIG. 8A, FIG. 10 illustrates a cross-sectional view of animproved single-shoulder connection 1000 with an angled primary shoulder1050 according to an embodiment of the present invention. As shown inFIGS. 8 and 10, the improved single-shoulder connection 800, 1000comprises a box connection 810, 1010 having a box axis (centerline) 812,a pin connection 830, 1030 having a pin axis (centerline) 832, and aprimary shoulder 850, 1050.

In an embodiment, the primary shoulder 850, 1050 comprises a primary boxshoulder 852, 1052 at a primary box angle 854 with respect to a firstperpendicular 880 to the box axis 812 at a first end point 882 to thebox connection; and a primary pin shoulder 856, 1056 at a primary pinangle 858 with respect to the first perpendicular 880 to the pin axis832 at the first end point 882 of the pin connection. See also FIG. 1A:112 & FIG. 1B: 132 (showing box and pin made-up). In an embodiment, thefirst end point 882 may be equal to a datum intersection, as discussedbelow.

Optional Box Boreback and Pin Stress Relief Groove with ImprovedSingle-Shoulder Connections with Curved Primary Shoulder

An optional box boreback 2370 may be applied to a single-shoulderconnection 2100, 2200, 2300, 2400 at portion(s) where fatigue may occuras a result of bending; and an optional pin stress relief groove 2390may be applied to a double-shoulder connection 1700, 1800, 1900, 2000,2400, 2600 or a single-shoulder connection 2100, 2200, 2300, 2400 atportion(s) where fatigue may occur as a result of bending. FIG. 23illustrates a cross-sectional view of an improved single-shoulderconnection with an optional box boreback 2370 and an optional pin stressrelief groove 2390 according to an embodiment of the present invention.As shown in FIG. 23, the optional box boreback 2370 and/or the optionalpin stress relief groove 2390 removes unengaged threads in potentiallystressed portions of the single-shoulder connection 2300 so that anybending occurs in portions with smooth surfaces that are relatively freeof stress concentrations.

Similar to FIG. 21A, FIG. 23 illustrates a cross-sectional view of animproved single-shoulder connection 2100, 2300 with a curved primaryshoulder 2150, 2350 according to an embodiment of the present invention.As shown in FIGS. 21 and 23, the improved single-shoulder connection2100, 2300 comprises a box connection 2110, 2310 having a box axis(centerline) 2112, a pin connection 2130, 2330 having a pin axis(centerline) 2132, and a primary shoulder 2150, 2350.

In an embodiment, the curved primary shoulder 2150, 2350 comprises aprimary box shoulder 2152, 2352; and a primary pin shoulder 2156, 2356.See also FIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made-up).

Types of Thread Forms

FIG. 11 illustrates a cross-sectional detailed view of a thread form1100 according to an embodiment of the present invention. As shown inFIG. 11, the thread form 1100 comprises a first thread crest 1110, asecond thread crest 1120, a first thread flank 1130, a second threadflank 1140, an included angle 1150 between the first thread flank 1130and second thread flank 1140, and a thread root 1160.

In an embodiment, any suitable thread form 1100 may be used for the boxthreads 426, 526, 626, 726, 826, 926, 1026, 1726, 1826, 1926, 2026,2126, 2226, 2326, 2426, 2626 and/or pin threads 446, 546, 646, 746, 846,946, 1046, 1746, 1846, 1946, 2046, 2146, 2246, 2346, 2446, 2646. Forexample, suitable shapes include, but are not limited to, circular,square, triangular, trapezoidal and variations thereof. In anembodiment, the thread form 1100 may be triangle shaped or a variationthereof.

For example, any suitable shape for the first thread crest 1110 and/orthe second thread crest 1120 may be used for the box threads 426, 526,626, 726, 826, 926, 1026, 1726, 1826, 1926, 2026, 2126, 2226, 2326,2426, 2626 and/or pin threads 446, 546, 646, 746, 846, 946, 1046, 1746,1846, 1946, 2046, 2146, 2246, 2346, 2446, 2646. For example, suitableshapes include, but are not limited to, circular, square, triangular,trapezoidal and variations thereof. In an embodiment, the first threadcrest 1110 and/or the second thread crest 1120 may be triangle shaped ora variation thereof.

For example, any suitable shape for the first thread flank 1130 and/orthe second thread flank 1140 may be used for the box threads 426, 526,626, 726, 826, 926, 1026, 1726, 1826, 1926, 2026, 2126, 2226, 2326,2426, 2626 and/or pin threads 446, 546, 646, 746, 846, 946, 1046, 1746,1846, 1946, 2046, 2146, 2246, 2346, 2446, 2646. For example, suitableshapes include, but are not limited to, concave, convex, straight andcombinations or variations thereof.

In an embodiment, any suitable shape for the thread root 1160 may beused for the box threads 426, 526, 626, 726, 826, 926, 1026, 1726, 1826,1926, 2026, 2126, 2226, 2326, 2426, 2626 and/or pin threads 446, 546,646, 746, 846, 946, 1046, 1746, 1846, 1946, 2046, 2146, 2246, 2346,2446, 2646. For example, suitable shapes include, but are not limitedto, circular, square, triangular, trapezoidal and variations thereof. Inan embodiment, the thread root 1160 may be triangle shaped or avariation thereof.

In an embodiment, any suitable included angle 1150 may be used for thebox threads 426, 526, 626, 726, 826, 926, 1026, 1726, 1826, 1926, 2026,2126, 2226, 2326, 2426, 2626 and/or pin threads 446, 546, 646, 746, 846,946, 1046, 1746, 1846, 1946, 2046, 2146, 2246, 2346, 2446, 2646. Forexample, suitable included angles 1150 may be from about 29 degrees toabout 90 degrees, and any range or value there between. In anembodiment, the included angle 1150 may be about 60 degrees.

Optional Thread Treatments

An optional thread treatment may be applied to the box threads 426, 526,626, 726, 826, 926, 1026, 1726, 1826, 1926, 2026, 2126, 2226, 2326,2426, 2626 and/or the pin threads 446, 546, 646, 746, 846, 946, 1046,1746, 1846, 1946, 2046, 2146, 2246, 2346, 2446, 2646 where fatigue mayoccur. In an embodiment, any suitable optional thread treatment may beapplied to the box threads 426, 526, 626, 726, 826, 926, 1026, 1726,1826, 1926, 2026, 2126, 2226, 2326, 2426, 2626 and/or pin threads 446,546, 646, 746, 846, 946, 1046, 1746, 1846, 1946, 2046, 2146, 2246, 2346,2446, 2646. For example, suitable thread treatments include, but are notlimited to, cold rolling, shot peening, phosphating, fluoropolymercoating, ceramic coating, chrome plating, anodizing, and combinations orvariations thereof. In an embodiment, the optional thread treatment maybe cold rolling or shot peening or fluoropolymer coating or anodizing.

Method for Determining a Primary Connection Shoulder Location withAngled Primary Shoulder

FIG. 12 illustrates a cross-sectional view of an improved primaryconnection shoulder 1200 according to an embodiment of the presentinvention.

As shown in FIG. 12, a pitch diameter (i.e., two times the pitch radius1270) intersects a pitch line 1272 at a first intersection 1274. A firstperpendicular 1276 to the connection box/pin axis 1212, 1232 may beoffset a first distance 1278 towards a primary box/pin shoulder 1250 tolocate a second perpendicular 1280 to the connection box/pin axis 1212,1232 at the first distance 1278. The pitch line 1272 intersects thesecond perpendicular 1280 at a second intersection 1282. In anembodiment, the second intersection 1282 may be equal to a datumintersection.

In an embodiment, the first distance 1278 may be from about 0.5 inch toabout 2.50 inches, and any range or value there between. In anembodiment, the first distance 1278 may be from about 0.625 inch toabout 2.250 inches. In an embodiment, the first distance 1278 may beabout 0.625 inch.

In an embodiment, the primary shoulder 1250 comprises a primary boxshoulder 1252 at a primary box angle 1254 with respect to a secondperpendicular 1280 to the box axis 1212 at a second intersection 1282 ofthe box connection; and a primary pin shoulder 1256 at a primary pinangle 1258 with respect to the second perpendicular 1280 to the pin axis1232 at the second intersection 1282 of the pin connection. See alsoFIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made-up). In anembodiment, the second intersection 1282 may be equal to a datumintersection.

In an embodiment, the primary box shoulder 1252 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary shoulder 1252 may beconical shaped (outside of cone, male).

In an embodiment, the primary pin shoulder 1256 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary pin shoulder 1256 maybe conical shaped (inside of cone, female).

In an embodiment, the primary box shoulder 1252 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary box shoulder 1252 may bean angled profile defined by a primary box angle 1254, as discussedbelow.

In an embodiment, the primary box angle 1254 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary box angle 1254 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary box angle 1254 may be about 5degrees.

In an embodiment, the primary pin shoulder 1256 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary pin shoulder 1256 may bean angled profile defined by a primary pin angle 1258, as discussedbelow.

In an embodiment, the primary pin angle 1258 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary pin angle 1258 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary pin angle 1258 may be about 5degrees.

In an embodiment, the primary box angle 1254 may be about equal to theprimary pin angle 1258 to form a first seal.

In an embodiment, the primary box angle 1254 may be slightly differentfrom the primary pin angle 1258 to form a first seal. In an embodiment,the first seal may be a gas-tight seal.

FIG. 13 illustrates a flowchart of a method to determine a primaryconnection shoulder location 1300 according to an embodiment of thepresent invention. As shown in FIG. 13, the method 1300 compriseslocating a pitch line parallel to a connection box/pin taper 1302;locating a first intersection of a pitch diameter and the pitch line1304; locating a first perpendicular to a connection box/pin axis at thefirst intersection 1306; locating a second perpendicular to theconnection pin/box axis at a first distance towards a primary box/pinshoulder from the first perpendicular (and parallel to the firstperpendicular) 1308; and locating a second intersection of the pitchline and the second perpendicular 1310.

In an embodiment, the method 1300 further comprises defining a primarybox/pin angle with respect to the second perpendicular at the secondintersection 1312.

Method for Determining a Primary Connection Shoulder Location withCurved Primary Shoulder

FIGS. 24A, 24B-1 and 24B-2 illustrate cross-sectional views of animproved primary connection shoulder 2400 according to an embodiment ofthe present invention.

As shown in FIGS. 24A and 24B-1, a pitch diameter (i.e., two times thepitch radius 2470) intersects a pitch line 2472 at a first intersection2474. A first perpendicular 2476 to the connection box/pin axis 2412,2432 may be offset a first distance 2478 towards a primary box/pinshoulder 2450 to locate a second perpendicular 2480 to the connectionbox/pin axis 2412, 2432 at the first distance 2478. The pitch line 2472intersects the second perpendicular 2480 at a second intersection 2482.In an embodiment, the second intersection 2482 may be equal to a datumintersection.

In an embodiment, the first distance 2478 may be from about 0.5 inch toabout 2.50 inches, and any range or value there between. In anembodiment, the first distance 2478 may be from about 0.625 inch toabout 2.250 inch. In an embodiment, the first distance 2478 may be about0.625 inches.

In an embodiment, a first reference plane 2482 a may be co-planer withthe second perpendicular 2480 and perpendicular to the connectionbox/pin axis 2412, 2432.

In an embodiment, the primary shoulder 2450 comprises a primary boxshoulder 2452; and a primary pin shoulder 2456. See also FIG. 1A: 112 &FIG. 1B: 132 (showing box and pin made-up).

Primary Box Shoulder

In an embodiment, the primary box shoulder 2452 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the primary shoulder 2452 may be convex shaped.

In an embodiment, the primary box shoulder 2452 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles, curved profiles, and variations thereof. In anembodiment, the primary box shoulder 2452 may be a curved profiledefined by a primary axial box radius height 2490, a primary box centerpoint 2492 and a primary box radius 2494, as discussed below.

In an embodiment, the primary axial box radius height 2490 may be fromabout 0.000 inch to about the length of the primary box radius 2494 ininches, and any range or value there between.

In an embodiment, the primary box center point 2492 may be locatedbetween the box counter bore diameter (i.e., two times box counter boreradius 118) and the pin bevel diameter (i.e., two times the pin bevelradius 136), and any range or value there between. In an embodiment, theprimary box center point 2492 may be about half-way between the boxcounter bore diameter (i.e., two times a box counter bore radius 118)and the pin bevel diameter (i.e., two times a pin bevel radius 136). Inan embodiment, the primary box center point 2492 may be located at about[(pin bevel diameter (i.e., two times pin bevel radius 136)+box counterbore diameter (i.e., two times box counter bore radius 118))/2].

In an embodiment, the primary box radius 2494 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches.

In an embodiment, the primary box radius 2494 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches.

Primary Pin Shoulder

In an embodiment, the primary pin shoulder 2456 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the primary pin shoulder 2456 may be concave shaped.

In an embodiment, the primary pin shoulder 2456 may be any suitableprofile. For example, suitable profiles include, but are not limited to,curved profiles, and variations thereof. In an embodiment, the primarypin shoulder 2456 may be a curved profile defined by a primary axial pinradius height 2496, a primary pin center point 2498 and a primary pinradius 24100, as discussed below.

In an embodiment, the primary axial pin radius height 2496 may be fromabout 0.000 inch to about the length of the primary pin radius 24100 ininches, and any range or value there between.

In an embodiment, the primary axial box radius height 2490 may be aboutequal to the primary axial pin radius height 2496.

In an embodiment, the primary pin center point 2498 may be locatedbetween the box counter bore diameter (i.e., two times box counter boreradius 118) and the pin bevel diameter (i.e., two times the pin bevelradius 136), and any range or value there between. In an embodiment, theprimary pin center point 2498 may be about half-way between the boxcounter bore diameter (i.e., two time a box counter bore radius 118) andthe pin bevel diameter (i.e., two times a pin bevel radius 136). In anembodiment, the primary pin center point 2498 may be located at about[(pin bevel diameter (i.e., two times pin bevel radius 136)+box counterbore diameter (i.e., two times box counter bore radius 118))/2] inches.

In an embodiment, the primary pin radius 24100 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches.

In an embodiment, the primary pin radius 24100 may be greater than about[(pin bevel diameter (i.e., two times pin bevel radius 136)−box counterbore diameter (i.e., two times box counter bore radius 118))/4] inches.

In an embodiment, the primary box radius 2494 may be about equal to theprimary pin radius 24100 to form a first seal. In an embodiment, theprimary box radius 2494 may be slightly different from the primary pinradius 24100 to form a first seal. In an embodiment, the first seal maybe a gas-tight seal.

As shown in FIG. 24B-2, the primary box shoulder 2452 may have a firstflat region 24114 at an inner edge of the curved profile and/or a firstangled region 24116 at an outer edge of the curved profile.

In an embodiment, the first flat region 24114 may be co-planer with thefirst reference plane 2482 a and perpendicular to the connection axis2412, 2432.

In an embodiment, the first angled region 24116 may be at a first angledregion angle 24118 with respect to a first offset reference plane 2482b. In an embodiment, the first offset reference plane 2482 b may be afirst offset distance 24120 from the first reference plane 2482 atowards the box threads 2426.

In an embodiment, the first angled region angle 24118 may be from about10 degrees to about 65 degrees, and any range or value there between. Inan embodiment, the first angled region angle 24118 may be from about 15degrees to about 60 degrees. In an embodiment, the first angled regionangle 24118 may be about 45 degrees.

In an embodiment, the first offset distance 24120 may be from about0.010 inch to about 0.030 inch, and any range or value there between. Inan embodiment, the first offset distance 24120 may be about 0.015 inch.

As shown in FIG. 24B-2, the primary pin shoulder 2456 may have a secondflat region 24122 at an inner edge of the curved profile and/or a thirdflat region 24124 at an outer edge of the curved profile.

In an embodiment, the second flat region 24122 at the inner edge of thecurved profile may be coplanar with a second offset reference plane 2482c. In an embodiment, the second offset reference plane 2482 c may be asecond offset distance 24126 from the first reference plane 2482 a awayfrom the pin threads 2446.

In an embodiment, the second flat distance 24126 may be from about 0.010inch to about 0.030 inch, and any range or value there between. In anembodiment, the second flat distance 24126 may be about 0.015 inch.

In an embodiment, the third flat region 24124 at the outer edge of thecurved profile may be co-planer with the first reference plane 2482 a.

FIG. 24C illustrates a cross-sectional view of an improved primaryconnection shoulder 2400 according to an embodiment of the presentinvention.

As shown in FIG. 24C, a pitch diameter (i.e., two times the pitch radius2470) intersects a pitch line 2472 at a first intersection 2474. A firstperpendicular 2476 to the connection box/pin axis 2412, 2432 may beoffset a first distance 2478 towards a primary box/pin shoulder 2450 tolocate a second perpendicular 2480 to the connection box/pin axis 2412,2432 at the first distance 2478. The pitch line 2472 intersects thesecond perpendicular 2480 at a second intersection 2482. In anembodiment, the second intersection 2482 may be equal to a datumintersection

In an embodiment, the first distance 2478 may be from about 0.5 inch toabout 2.50 inches, and any range or value there between. In anembodiment, the first distance 2478 may be from about 0.625 inch toabout 2.250 inches. In an embodiment, the first distance 2478 may beabout 0.625 inch.

In an embodiment, the primary shoulder 2450 comprises a primary boxshoulder 2452 at a primary box angle 2454 with respect to a secondperpendicular 2480 to the box axis 2412 at a second intersection 2482 ofthe box connection; and a primary pin shoulder 2456 at a primary pinangle 2458 with respect to the second perpendicular 2480 to the pin axis2432 at the second intersection 2482 of the pin connection. See alsoFIG. 1A: 112 & FIG. 1B: 132 (showing box and pin made-up). In anembodiment, the second intersection 2482 may be equal to a datumintersection.

In an embodiment, the primary box shoulder 2452 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary shoulder 2452 may beconical shaped (outside of cone, male).

In an embodiment, the primary pin shoulder 2456 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the primary pin shoulder 2456 maybe conical shaped (inside of cone, female).

In an embodiment, the primary box shoulder 2452 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary box shoulder 2452 may bean angled profile defined by a primary box angle 2454, as discussedbelow.

In an embodiment, the primary box angle 2454 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary box angle 2454 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary box angle 2454 may be about 5degrees. In an embodiment, the primary box angle 2454 may be about 0degrees.

In an embodiment, the primary pin shoulder 2456 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the primary pin shoulder 2456 may bean angled profile defined by a primary pin angle 2458, as discussedbelow.

In an embodiment, the primary pin angle 2458 may be from greater thanabout 0 degrees to less than or equal to about 15 degrees, and any rangeor value there between. In an embodiment, the primary pin angle 2458 maybe from greater than about 0 degrees to less than or equal to about 10degrees. In an embodiment, the primary pin angle 2458 may be about 5degrees. In an embodiment, the primary pin angle 2458 may be about 0degrees.

In an embodiment, the primary box angle 2454 may be about equal to theprimary pin angle 2458 to form a first seal.

In an embodiment, the primary box angle 2454 may be slightly differentfrom the primary pin angle 2458 to form a first seal. In an embodiment,the first seal may be a gas-tight seal.

FIG. 25 illustrates a flowchart of a method to determine a primaryconnection shoulder location 2500 according to an embodiment of thepresent invention. As shown in FIG. 25, the method 2500 compriseslocating a pitch line parallel to a connection box/pin taper 2502;locating a first intersection of a pitch diameter and the pitch line2504; locating a first perpendicular to a connection box/pin axis at thefirst intersection 2506; locating a second perpendicular to theconnection pin/box axis at a first distance towards a primary box/pinshoulder from the first perpendicular (and parallel to the firstperpendicular) 2508; and locating a first reference plane co-planer withthe second perpendicular and perpendicular to the connection box/pinaxis, and, optionally, locating a second intersection of the pitch lineand the second perpendicular 2510.

In an embodiment, the method 2500 further comprises selecting a primaryaxial box/pin radius height, selecting a primary box/pin radius andlocating a primary box/pin center point between a box counter borediameter and a pin bevel diameter 2512.

In an embodiment, the method 2500 further comprises, defining a primarybox/pin curved profile with respect to primary axial box/pin radiusheight, the primary box/pin center point and the primary box/pin radius,and, optionally, defining a primary box/pin angle with respect to thesecond perpendicular at the second intersection 2514.

Method for Determining a Secondary Connection Shoulder Location withAngled Secondary Shoulder

FIG. 14 illustrates a cross-sectional view of an improved secondaryconnection shoulder 1400 according to an embodiment of the presentinvention. As discussed above with respect to FIG. 12, the pitch line1272 intersects the second perpendicular 1280, 1480 at a secondintersection 1282. In an embodiment, the second intersection 1282 may beequal to a datum intersection.

A second perpendicular 1480 to the connection box/pin axis 1412, 1432may be offset a second distance 1484 towards a secondary box/pinshoulder 1460 to locate a third perpendicular 1486 to the connectionbox/pin axis 1412, 1432 at the second distance 1484.

The pin nose outer diameter (i.e., two times pin nose radius 1440)intersects the third perpendicular 1486 at a third intersection 1488.

In an embodiment, the second distance 1484 may be any suitable distance.In an embodiment, the second distance 1484 may be equal to theconnection length. The connection length varies with connection size.

In an embodiment, the second distance 1484 may be about 2 inches toabout 8 inches, and any range or value there between.

In an embodiment, the secondary shoulder 1460 comprises a secondary boxshoulder 1462 at a secondary box angle 1464 with respect to a thirdperpendicular 1486 to the box axis 1412 at a third intersection 1488 ofthe box connection; and a secondary pin shoulder 1466 at a secondary pinangle 1468 with respect to the third perpendicular 1486 to the pin axis1432 at the third intersection 1488 of the pin connection. See also FIG.1A: 112 & FIG. 1B: 132 (showing box and pin made-up).

In an embodiment, the secondary box shoulder 1462 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the secondary shoulder 1462 may beconical shaped (outside of cone, male).

In an embodiment, the secondary pin shoulder 1466 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the secondary pin shoulder 1466may be conical shaped (inside of cone, female).

In an embodiment, the secondary box shoulder 1462 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the secondary box shoulder 1462 maybe an angled profile defined by a secondary box angle 1464, as discussedbelow.

In an embodiment, the secondary box angle 1464 may be from greater thanor equal to about 0 degrees to less than or equal to about 15 degrees,and any range or value there between. In an embodiment, the secondarybox angle 1464 may be from greater than or equal to about 0 degrees toless than or equal to about 10 degrees. In an embodiment, the secondarybox angle 1464 may be about 5 degrees.

In an embodiment, the secondary pin shoulder 1466 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the secondary pin shoulder 1466 maybe an angled profile defined by a secondary pin angle 1468, as discussedbelow.

In an embodiment, the secondary pin angle 1468 may be from greater thanor equal to about 0 degrees to less than or equal to about 15 degrees,and any range or value there between. In an embodiment, the secondarypin angle 1468 may be from greater than or equal to about 0 degrees toless than or equal to about 10 degrees. In an embodiment, the secondarypin angle 1468 may be about 5 degrees.

In an embodiment, the secondary box angle 1464 may be about equal to thesecondary pin angle 1468 to form a torque shoulder.

In an embodiment, the secondary box angle 1464 may be slightly differentfrom the secondary pin angle 1468 to form a torque shoulder that is asecond seal. In an embodiment, the torque shoulder or second seal may bea gas-tight seal.

FIG. 15 illustrates a flowchart of a method to determine a secondaryconnection shoulder location 1500 according to an embodiment of thepresent invention. As shown in FIG. 15, the method 1500 compriseslocating a pitch line parallel to a connection box/pin taper 1502;locating a first intersection of a pitch diameter and the pitch line1504; locating a first perpendicular to the connection box/pin axis atthe first intersection 1506; locating a second perpendicular to theconnection pin/box axis at a first distance towards a primary box/pinshoulder from the first perpendicular (and parallel to the firstperpendicular) 1508; locating a second intersection of the pitch lineand the second perpendicular 1510; optionally, defining a primarybox/pin angle with respect to the second perpendicular at the secondintersection 1512; locating a third perpendicular to the connectionbox/pin axis at a second distance (connection length) toward a secondarybox/pin shoulder (and parallel to the second perpendicular) 1514; andlocating a third intersection of a pin nose outer diameter and the thirdperpendicular 1516.

In an embodiment, the method 1500 further comprises defining a secondarybox/pin angle with respect to the third perpendicular at the thirdintersection 1518.

Method for Determining a Secondary Connection Shoulder Location withCurved Secondary Shoulder

FIGS. 26A, 26B-1 and 26B-2 illustrate cross-sectional views of animproved secondary connection shoulder 2600 according to an embodimentof the present invention. As discussed above with respect to FIG. 24,the pitch line 2472 intersects the second perpendicular 2480, 2680 at asecond intersection 2482, 2682. In an embodiment, the secondintersection 2482, 2682 may be equal to a datum intersection.

As shown in FIGS. 26A and 26B-1, a second perpendicular 2680 to theconnection box/pin axis 2612, 2632 may be offset a second distance 2684towards a secondary box/pin shoulder 2660 to locate a thirdperpendicular 2686 to the connection box/pin axis 2612, 2632 at thesecond distance 2684.

The pin nose outer diameter (i.e., two times the pin radius 2640)intersects the third perpendicular 2686 at a third intersection 2688.

In an embodiment, the second distance 2684 may be any suitable distance.In an embodiment, the second distance 2684 may be equal to theconnection length. The connection length varies with connection size.

In an embodiment, the second distance 2684 may be from about 1 inch toabout 8 inches, and any range or value there between. In an embodiment,the second distance 2684 may be from about 2 inches to about 8 inches.

In an embodiment, the secondary shoulder 2660 comprises a secondary boxshoulder 2662; and a secondary pin shoulder 2666. See also FIG. 1A: 112& FIG. 1B: 132 (showing box and pin made-up).

Secondary Box Shoulder

In an embodiment, the secondary box shoulder 2662 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the secondary shoulder 2662 may be concave shaped.

In an embodiment, the secondary box shoulder 2662 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles, curved profiles, and variations thereof. In anembodiment, the secondary box shoulder 2662 may be a curved profiledefined by a secondary axial box radius height 26102, a secondary boxcenter point 26104 and a secondary box radius 26106, as discussed below.

In an embodiment, the secondary axial box radius height 26102 may befrom about 0.000 inch to about the length of the secondary box radius26106 in inches, and any range or value there between.

In an embodiment, the secondary box center point 26104 may be locatedbetween a pin nose outer diameter (i.e., two times pin nose radius 140)and a pin nose inner diameter (i.e., two times pin nose inner radius 240a), and any range or value there between. In an embodiment, thesecondary box center point 26104 may be located about half-way between apin nose outer diameter (i.e., two times pin nose radius 140) and a pinnose inner diameter (i.e., two times pin nose inner radius 240 a). In anembodiment, the secondary box center point 26104 may be located about[(pin nose outer diameter (i.e., two times pin nose radius 140)+pin noseinner diameter (i.e., two times pin nose inner radius 240 a))/2].

In an embodiment, the secondary box radius 26106 may be greater thanabout [(pin nose outer diameter (i.e., two times pin nose radius140)−pin nose inner diameter (i.e., two times pin nose inner radius 240a))/4] inches, and any range or value there between.

Secondary Pin Shoulder

In an embodiment, the secondary pin shoulder 2666 may be any suitableshape. For example, suitable shapes include, but are not limited to,concave shaped, conical shaped, convex shaped, cylindrical shaped,conical-cylindrical shaped, and variations thereof. In an embodiment,the secondary pin shoulder 2666 may be convex shaped.

In an embodiment, the secondary pin shoulder 2666 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles, curved profiles, and variations thereof. In anembodiment, the secondary pin shoulder 2666 may be a curved profiledefined by a secondary axial pin radius height 26108, a secondary pincenter point 26110 and a secondary pin radius 26112, as discussed below.

In an embodiment, the secondary axial pin radius height 26108 may befrom about 0.000 inch to about the length of the secondary pin radius26112 in inches, and any range or value there between.

In an embodiment, the secondary axial box radius height 26102 may beabout equal to the secondary pin axial height 26108.

In an embodiment, the secondary pin center point 26110 may be locatedbetween a pin nose outer diameter (i.e., two times pin nose radius 140)and a pin nose inner diameter (i.e., two time pin nose inner radius 240a), and any range or value there between. In an embodiment, thesecondary pin center point 26110 may be located about half-way between apin nose outer diameter (i.e., two times pin nose radius 140) and a pinnose inner diameter (i.e., two times pin nose inner radius 240 a). In anembodiment, the secondary pin center point 26110 may be located about[(pin nose outer diameter (i.e., two times pin nose radius 140)+pin noseinner diameter (i.e., two times pin nose inner radius 240 a))/2].

In an embodiment, the secondary pin radius 26112 may be greater thanabout [(pin nose outer diameter (i.e., two times pin nose radius140)−pin nose inner diameter (i.e., two times pin nose inner radius 240a))/4] inches, and any range or value there between.

In an embodiment, the secondary box center point 26104 may be aboutequal to the secondary pin center point 26110.

In an embodiment, the secondary box radius 26106 may be about equal tothe secondary pin radius 26112 to form a torque shoulder.

In an embodiment, the secondary box radius 26106 may be slightlydifferent from the secondary pin radius 26112 to form a torque shoulderthat is a second seal. In an embodiment, the torque shoulder or thesecond seal may be a gas-tight seal.

As shown in FIG. 26B-2, the secondary box shoulder 2662 may have afourth flat region 26128 at an inner edge of the curved profile and/or afifth flat region 26130 at an outer edge of the curved profile.

In an embodiment, the fourth flat region 26128 at the inner edge of thecurved profile may be coplanar with a third offset reference plane 2688b. In an embodiment, the third offset reference plane 2688 b may be athird offset distance 26132 from the second reference plane 2688 a awayfrom the box threads 2626.

In an embodiment, the third offset distance 26132 may be from about0.010 inch to about 0.030 inch, and any range or value there between. Inan embodiment, the third offset distance 26132 may be about 0.015 inch.

In an embodiment, the fifth flat region 26130 at the outer edge of thecurved profile may be co-planer with the second reference plane 2688 aand perpendicular to the connection axis 2612, 2632.

As shown in FIG. 26B-2, the secondary pin shoulder 2666 may have a sixthflat region 26134 at an inner edge of the curved profile and a secondangled region 26136 at an outer edge of the curved profile.

In an embodiment, the sixth flat region 26134 at the inner edge of thecurved profile may be co-planer with the second reference plane 2688 aand perpendicular to the connection axis 2612, 2632.

In an embodiment, the second angled region 26136 may be at a secondangled region angle 26138 with respect to a fourth offset referenceplane 2682 c. In an embodiment, the fourth offset reference plane 2688 cmay be a fourth offset distance 26140 from the second reference plane2688 a towards the pin threads 2646.

In an embodiment, the first angled region angle 24118 may be from about10 degrees to about 65 degrees, and any range or value there between. Inan embodiment, the second angled region angle 26138 may be from about 15degrees to about 60 degrees. In an embodiment, the second angled regionangle 26138 may be about 45 degrees.

In an embodiment, the fourth offset distance 26140 may be from about0.010 inch to about 0.030 inch, and any range or value there between. Inan embodiment, the fourth offset distance 26140 may be about 0.015 inch.

FIG. 26C illustrates a cross-sectional view of an improved secondaryconnection shoulder 2600 according to an embodiment of the presentinvention. As discussed above with respect to FIG. 24C, the pitch line2472 intersects the second perpendicular 2480, 2680 at a secondintersection 2482, 2682. In an embodiment, the second intersection 2682may be equal to a datum intersection.

A second perpendicular 2680 to the connection box/pin axis 2612, 2632may be offset a second distance 2684 towards a secondary box/pinshoulder 2660 to locate a third perpendicular 2686 to the connectionbox/pin axis 2612, 2632 at the second distance 2684.

The pin nose outer diameter (i.e., two times pin nose radius 2640)intersects the third perpendicular 2686 at a third intersection 2688.

In an embodiment, the second distance 2684 may be any suitable distance.In an embodiment, the second distance 2684 may be equal to theconnection length. The connection length varies with connection size.

In an embodiment, the second distance 2684 may be about 2 inches toabout 8 inches, and any range or value there between.

In an embodiment, the secondary shoulder 2660 comprises a secondary boxshoulder 2662 at a secondary box angle 2664 with respect to a thirdperpendicular 2686 to the box axis 2612 at a third intersection 2688 ofthe box connection; and a secondary pin shoulder 2666 at a secondary pinangle 2668 with respect to the third perpendicular 2686 to the pin axis2632 at the third intersection 2688 of the pin connection. See also FIG.1A: 112 & FIG. 1B: 132 (showing box and pin made-up).

Secondary Box Shoulder

In an embodiment, the secondary box shoulder 2662 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the secondary shoulder 2662 may beconical shaped (outside of cone, male).

In an embodiment, the secondary box shoulder 2662 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the secondary box shoulder 2662 maybe an angled profile defined by a secondary box angle 2664, as discussedbelow.

In an embodiment, the secondary box angle 2664 may be from greater thanor equal to about 0 degrees to less than or equal to 15 degrees, and anyrange or value there between. In an embodiment, the secondary box angle2664 may be from greater than or equal to about 0 degrees to less thanor equal to 10 degrees. In an embodiment, the secondary box angle 2664may be about 5 degrees. In an embodiment, the secondary box angle 2664may be about 0 degrees.

Secondary Pin Shoulder

In an embodiment, the secondary pin shoulder 2666 may be any suitableshape. For example, suitable shapes include, but are not limited to,conical shaped, cylindrical shaped, conical-cylindrical shaped, andvariations thereof. In an embodiment, the secondary pin shoulder 2666may be conical shaped (inside of cone, female).

In an embodiment, the secondary pin shoulder 2666 may be any suitableprofile. For example, suitable profiles include, but are not limited to,angled profiles. In an embodiment, the secondary pin shoulder 2666 maybe an angled profile defined by a secondary pin angle 2668, as discussedbelow.

In an embodiment, the secondary pin angle 2668 may be from greater thanor equal to about 0 degrees to less than or equal to 15 degrees, and anyrange or value there between. In an embodiment, the secondary pin angle2668 may be from greater than or equal to about 0 degrees to less thanor equal to 10 degrees. In an embodiment, the secondary pin angle 2668may be about 5 degrees. In an embodiment, the secondary pin angle 2668may be about 0 degrees.

In an embodiment, the secondary box angle 2664 may be about equal to thesecondary pin angle 2668 to form a torque shoulder.

In an embodiment, the secondary box angle 2664 may be slightly differentfrom the secondary pin angle 2668 to form a torque shoulder that is asecond seal. In an embodiment, the torque shoulder or the second sealmay be a gas-tight seal.

FIG. 27 illustrates a flowchart of a method to determine a secondaryconnection shoulder location 2700 according to an embodiment of thepresent invention. As shown in FIG. 27, the method 2700 compriseslocating a pitch line parallel to a connection box/pin taper 2702;locating a first intersection of a pitch diameter and the pitch line2704; locating a first perpendicular to the connection box/pin axis atthe first intersection 2706; locating a second perpendicular to theconnection pin/box axis at a first distance towards a primary box/pinshoulder from the first perpendicular (and parallel to the firstperpendicular) 2708; locating a first reference plane, and, optionally,locating a second intersection of the pitch line and the secondperpendicular 2710; selecting a primary axial box/pin radius height,selecting a primary box/pin radius, and locating a primary box/pincenter point between a box counter bore diameter and a pin beveldiameter 2712; defining a primary box/pin curved profile with respect toprimary axial box/pin radius height, the primary box/pin center pointand the primary box/pin radius, and, optionally, defining a primarybox/pin angle with respect to the second perpendicular at the secondintersection 2714; locating a third perpendicular to the connectionbox/pin axis at a second distance (connection length) toward a secondarybox/pin shoulder (and parallel to the second perpendicular) 2716; andlocating a second reference plane, and, optionally, locating a thirdintersection of a pin nose outer diameter and the third perpendicular2718.

In an embodiment, the method 2700 further comprises selecting asecondary axial box/pin radius height, selecting a secondary box/pinradius, and locating a secondary box/pin center point between a pin noseouter diameter and a pin nose inner diameter 2720.

In an embodiment, the method 2700 further comprises, defining asecondary box/pin curved profile with respect to secondary axial box/pinradius height, the secondary box/pin center point and the secondarybox/pin radius, and, optionally, defining a secondary box/pin angle withrespect to the third perpendicular at the third intersection 2722.

Method of Using Improved Double-Shoulder Connection with Angled PrimaryShoulder or Improved Single-Shoulder Connection with Angled PrimaryShoulder

FIG. 16 illustrates a flowchart of a method of using an improveddouble-shoulder connection with an angled primary shoulder or animproved single-shoulder connection with an angled primary shoulder 1600according to an embodiment of the present invention. As shown in FIG.16, the method 1600 comprises providing a rotary shoulder connection1602, and applying the rotary shoulder connection to one or moreproducts 1604.

In an embodiment, the rotary shoulder connection may be the improveddouble-shoulder connection 400, 500, 700 with an angled primary shoulder450, 550, 750 or the improved double-shoulder connection 600 with anangled secondary shoulder 660, or the improved single-shoulderconnection 800, 900, 1000 with an angled primary shoulder 850, 950,1050, as discussed above.

In an embodiment, the rotary shoulder connection may be the improveddouble-shoulder connection 400, 500, 600, 700 with an angled primaryshoulder 450, 550, 750 and/or an angled secondary shoulder 660, 760, asdiscussed above.

In an embodiment, the method 1600 further comprises tightening therotary shoulder connection between the one or more products to form afirst seal at an angled primary shoulder 450, 550, 650, 750, 850, 950,1050.

In an embodiment, the method 1600 further comprises tightening therotary shoulder connection between the one or more products to form afirst seal at an angled primary shoulder 450, 550, 750 and/or a torqueshoulder at an angled secondary shoulder 660, 760.

Method of Using Improved Double-Shoulder Connection with Curved PrimaryShoulder or Improved Single-Shoulder Connection with Curved PrimaryShoulder

FIG. 28 illustrates a flowchart of a method of using an improveddouble-shoulder connection with a curved primary shoulder or an improvedsingle-shoulder connection with a curved primary shoulder 2800 accordingto an embodiment of the present invention. As shown in FIG. 24, themethod 2800 comprises providing a rotary shoulder connection 2802, andapplying the rotary shoulder connection to one or more products 2804.

In an embodiment, the rotary shoulder connection may be the improveddouble-shoulder connection 1700, 1800, 2000, 2400 with a curved primaryshoulder 1750, 1850, 2050, 2450 or the improved double-shoulderconnection 1900 with a curved secondary shoulder 1960, or the improvedsingle-shoulder connection 2100, 2200, 2300, 2400 with a curved primaryshoulder 2150, 2250, 2350, 2450, as discussed above.

In an embodiment, the rotary shoulder connection may be the improveddouble-shoulder connection 1700, 1800, 1900, 2000, 2400, 2600 with acurved primary shoulder 1750, 1850, 2050, 2450 and/or a curved secondaryshoulder 1960, 2060, 2660, as discussed above.

In an embodiment, the method 2800 further comprises tightening therotary shoulder connection between the one or more products to form afirst seal at an angled primary shoulder 1750, 1850, 1950, 2050, 2150,2250, 2350, 2450.

In an embodiment, the method 2800 further comprises tightening therotary shoulder connection between the one or more products to form afirst seal at a curved primary shoulder 1750, 1850, 2050, 2450.

In an embodiment, the method 2800 further comprises tightening therotary shoulder connection between one or more products to form a torqueshoulder at a curved secondary shoulder 1960, 2060, 2660.

In the foregoing description of certain embodiments, specificterminology has been resorted to for the sake of clarity. However, thedisclosure is not intended to be limited to the specific terms soselected, and it is to be understood that each specific term includesother technical equivalents which operate in a similar manner toaccomplish a similar technical purpose. Terms (e.g., “outer” and“inner,” “upper” and “lower,” “first” and “second,” “internal” and“external,” “above” and “below” and the like) are used as words ofconvenience to provide reference points and, as such, are not to beconstrued as limiting terms.

The embodiments set forth herein are presented to best explain thepresent invention and its practical application and to thereby enablethose skilled in the art to make and utilize the invention. However,those skilled in the art will recognize that the foregoing descriptionhas been presented for the purpose of illustration and example only. Thedescription as set forth is not intended to be exhaustive or to limitthe invention to the precise form disclosed. Many modifications andvariations are possible in light of the above teaching without departingfrom the spirit and scope of the following claims.

Also, the various embodiments described above may be implemented inconjunction with other embodiments, e.g., aspects of one embodiment maybe combined with aspects of another embodiment to realize yet otherembodiments. Further, each independent feature or component of any givenassembly may constitute an additional embodiment.

Definitions

As used herein, the terms “a,” “an,” “the,” and “said” mean one or more,unless the context dictates otherwise.

As used herein, the term “about” means the stated value plus or minus amargin of error plus or minus 10% if no method of measurement isindicated.

As used herein, the term “or” means “and/or” unless explicitly indicatedto refer to alternatives only or if the alternatives are mutuallyexclusive.

As used herein, the terms “comprising,” “comprises,” and “comprise” areopen-ended transition terms used to transition from a subject recitedbefore the term to one or more elements recited after the term, wherethe element or elements listed after the transition term are notnecessarily the only elements that make up the subject.

As used herein, the terms “containing,” “contains,” and “contain” havethe same open-ended meaning as “comprising,” “comprises,” and“comprise,” provided above.

As used herein, the terms “having,” “has,” and “have” have the sameopen-ended meaning as “comprising,” “comprises,” and “comprise,”provided above.

As used herein, the terms “including,” “includes,” and “include” havethe same open-ended meaning as “comprising,” “comprises,” and“comprise,” provided above.

As used herein, the phrase “consisting of” is a closed transition termused to transition from a subject recited before the term to one or morematerial elements recited after the term, where the material element orelements listed after the transition term are the only material elementsthat make up the subject.

As used herein, the phrase “material yields” means the material hasexceeded its modulus of elasticity.

As used herein, the term “simultaneously” means occurring at the sametime or about the same time, including concurrently.

Incorporation By Reference. All patents and patent applications,articles, reports, and other documents cited herein are fullyincorporated by reference to the extent they are not inconsistent withthis invention.

What is claimed is:
 1. A drill pipe comprising: (a) A drill pipe bodyhaving a drill pipe body outer diameter and a drill pipe body innerdiameter; and (b) A tool joint comprising a rotary shoulder boxconnection; (c) wherein the drill pipe has an optimization ratio (Ro)defined by${{Ro} = \frac{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}\mspace{14mu} {strength}}{{Geometric}\mspace{14mu} {Factors}\mspace{14mu} {which}\mspace{14mu} {affect}\mspace{14mu} {pressure}\mspace{14mu} {loss}}},$and (d) wherein the optimization ratio is at least about 0.68 for aproduction hole from about 7⅞-inches to about 12¼-inches.
 2. The drillpipe of claim 1, wherein the optimization ratio is at least about 0.68for a production hole of about 7⅞-inches.
 3. The drill pipe of claim 1,wherein the optimization ratio is at least about 0.70 for a productionhole of about 8½-inches.
 4. The drill pipe of claim 1, wherein theoptimization ratio is at least about 0.62 for a production hole of about12¼-inches.
 5. The drill pipe of claim 1, wherein the optimization ratiois at least about 0.68 for a production hole of about 7⅞-inches at aflow rate of 600 gpm of 12 pound per gallon mud.
 6. The drill pipe ofclaim 1, wherein the optimization ratio is at least about 0.70 for aproduction hole of about 8½-inches at a flow rate of about 600 gpm of 12pound per gallon mud.
 7. The drill pipe of claim 1, wherein theoptimization ratio is at least about 0.62 for a production hole of about12¼-inches at a flow rate of about 900 gpm of 12 pound per gallon mud.8. The drill pipe of claim 1, wherein the optimization ratio isapproximated by ${Ro} = {\frac{{Pod} - {Pid}}{{EQod} - {EQid}}.}$
 9. Thedrill pipe of claim 8, wherein the optimization ratio is at least about0.68 for a production hole of about 7⅞-inches.
 10. The drill pipe ofclaim 8, wherein the optimization ratio is at least about 0.70 for aproduction hole of about 8½-inches.
 11. The drill pipe of claim 8,wherein the optimization ratio is at least about 0.62 for a productionhole of about 12¼-inches.
 12. The drill pipe of claim 8, wherein theoptimization ratio is at least about 0.68 for a production hole of about7⅞-inches at a flow rate of 600 gpm of 12 pound per gallon mud.
 13. Thedrill pipe of claim 8, wherein the optimization ratio is at least about0.70 for a production hole of about 8½-inches at a flow rate of about600 gpm of 12 pound per gallon mud.
 14. The drill pipe of claim 8,wherein the optimization ratio is at least about 0.62 for a productionhole of about 12¼-inches at a flow rate of about 900 gpm of 12 pound pergallon mud.
 15. The drill pipe of claim 1, wherein the drill pipe bodyouter diameter is from about 5.1-inches to about 5.4-inches and thedrill pipe body inner diameter is from about 4.4-inches to about4.6-inches.
 16. The drill pipe of claim 1, wherein the drill pipe bodyouter diameter is about 5.25-inches and the drill pipe body innerdiameter is about 4.528-inches.
 17. The drill pipe of claim 1, whereinthe drill pipe body comprises: (a) A drill pipe body wall thickness,wherein the drill pipe body wall thickness is from about 0.352-inches toabout 0.370-inches.
 18. The drill pipe of claim 17, wherein the drillpipe body wall thickness is about 0.361-inch.
 19. The drill pipe ofclaim 1, wherein the drill pipe comprises: (a) A drill pipe length,wherein the drill pipe length is from about 25-feet to about 50-feet.20. The drill pipe of claim 19, wherein the drill pipe length is about31.5-feet.
 21. The drill pipe of claim 1, wherein the rotary shoulderconnection comprises: (a) A rotary shoulder connection length, whereinthe rotary shoulder connection length is from about 4.275-inches toabout 5.225-inches.
 22. The drill pipe of claim 21, wherein the rotaryshoulder connection length is about 4.75-inches.
 23. A method of using adrill pipe comprises: (a) Providing a plurality of the drill pipe ofclaim 1; (b) Connecting the plurality of the drill pipe to produce adrill string.
 24. The drill pipe of claim 23, wherein the optimizationratio is at least about 0.68 for a production hole of about 7⅞-inches.25. The drill pipe of claim 23, wherein the optimization ratio is atleast about 0.70 for a production hole of about 8½-inches.
 26. The drillpipe of claim 23, wherein the optimization ratio is at least about 0.62for a production hole of about 12¼-inches.
 27. A method of using a drillpipe comprises: (a) Providing a plurality of the drill pipe of claim 8;(b) Connecting the plurality of the drill pipe to produce a drillstring.
 28. The drill pipe of claim 27, wherein the optimization ratiois at least about 0.68 for a production hole of about 7⅞-inches.
 29. Thedrill pipe of claim 27, wherein the optimization ratio is at least about0.70 for a production hole of about 8½-inches.
 30. The drill pipe ofclaim 27, wherein the optimization ratio is at least about 0.62 for aproduction hole of about 12¼-inches.